Glucosamine derivatives for the prevention or treatment of joint disorders

ABSTRACT

There are provided compounds of Formula (A) and pharmaceutically acceptable salts and esters thereof, and pharmaceutical compositions thereof, used for the prevention or treatment in a mammal of joint and bone disorders such as arthritis and osteoporosis.

FIELD

The present disclosure relates to glucosamine derivatives, compositionsthereof, and methods of use thereof in therapeutic applications such asthe prevention and treatment of arthritis and osteoporosis.

BACKGROUND

Osteoporosis is a condition in which the bones become less dense andmore likely to fracture. In the United States, more than 53 millionpeople either already have osteoporosis or are at high risk due to lowbone mass. In osteoporosis, there is a loss of bone tissue that leavesbones less dense and more likely to fracture. It can result in a loss ofheight, severe back pain, and change in one's posture. Osteoporosis canimpair a person's ability to walk and can cause prolonged or permanentdisability.

Osteoporosis is known as a silent disease because it can progressundetected for many years without symptoms until a fracture occurs.Osteoporosis is diagnosed by a bone mineral density test, which is asafe and painless way to detect low bone density. The World HealthOrganization defines the presence of osteoporosis in humans in terms oflow bone mineral density BMD. Individuals whose BMD is less than 2.5standard deviations below the mean of young normals of their sex inrespect of peak bone mass, are considered to have osteoporosis.Individuals whose BMD is less than 1.0 standard deviations below peakbone mass of their sex, are considered to have osteopenia. Osteoporosisresults in a higher probability of fracturing bones. It is well knownthat women have a higher prevalence of osteoporosis and fracturescompared to males, and that there is an increased prevalence ofosteoporosis and associated increased incidence of fractures after themenopause. Low impact injuries can result in osteoporotic fractures, orso called “fragility fractures”. Fractures can occur also after highimpact, as a result of significant trauma, in individuals with normalbones or osteoporotic or osteopenic bones. The healing of high impactfractures depends on stimulation of new bone formation. Localosteoporosis can occur as a result of immobilization during thetreatment of the fracture.

Although BMD is a reasonably good predictor of the risk of fracture insites such as the hip or spine it is becoming increasingly recognizedthat there are a number of limitations to the usefulness of BMDmeasurements. One of the reasons is that DXA technology does not assessbone quality, which depends to a large extent on the micro-architectureof bone. Most drugs used in osteoporosis, such as the bi-phosphonates,increase BMD but do not improve the micro-architecture or theconnectivity of bone. Parathyroid hormone administration results in animprovement of trabecular architecture. Glucosamine-based syntheticcompounds are not known to improve BMD or bone microarchitecture.

Although currently there is no cure for the disease, the Food and DrugAdministration has approved several medications to prevent and treatosteoporosis. In addition, a diet rich in calcium and vitamin D, regularweight-bearing exercise, and a healthy lifestyle can prevent or lessenthe effects of the disease.

Arthritis is a general term for conditions that affect the joints andsurrounding tissues. Joints are places in the body where bones cometogether, such as the knees, wrists, fingers, toes, and hips. Two commontypes of arthritis are osteoarthritis and inflammatory arthritis, suchas rheumatoid arthritis.

Osteoarthritis (OA) is a painful, degenerative joint disease that ofteninvolves the hips, knees, neck, lower back, or small joints of thehands. OA usually develops in joints that are injured by repeatedoveruse from performing a particular task or playing a favorite sport orfrom carrying around excess body weight. Eventually this injury orrepeated impact thins or wears away the cartilage that cushions the endsof the bones in the joint. As a result, the bones rub together, causinga grating sensation. Joint flexibility is reduced, bony spurs develop,and the joint swells. Usually, the first symptom of OA is pain thatworsens following exercise or immobility. Treatment usually includesanalgesics, topical creams, or nonsteroidal anti-inflammatory drugs,appropriate exercises or physical therapy; joint splinting; or jointreplacement surgery for seriously damaged larger joints, such as theknee or hip. Glucosamine is a popular non-prescription, nutraceuticaltreatment for pain in OA.

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease thatusually involves various joints in the fingers, thumbs, wrists, elbows,shoulders, knees, feet, and ankles. An autoimmune disease is one inwhich the body releases enzymes that attack its own healthy tissues. InRA, these enzymes destroy the linings of joints. This causes pain,swelling, stiffness, malformation, and reduced movement and function.People with RA also may have systemic symptoms, such as fatigue, fever,weight loss, eye inflammation, anemia, subcutaneous nodules (bumps underthe skin), or pleurisy (a lung inflammation).

Subjects suffering from osteoporosis and arthritis share many copingstrategies. Many with one or both of these conditions benefit fromexercise programs that may include physical therapy and rehabilitation.However, there is no real cure for either or both of these conditionsand better treatments are needed.

Glycoconjugates play an important role in many biological processes.Carbohydrate groups can confer important physical properties such asconformational stability, protease resistance, charge and water-bindingcapacity, and biological recognition, where sequence diversity providessignals for protein targeting and cell-cell interactions (Paulson, J.C., Trends in Biochemical Sciences, 1989, 14(7): 272-6). Glycoconjugatesof connective tissue matrices consist of hexosamines that areN-acetylated. However, the function of the N-acetyl moiety is not known.

The benefit of glucosamine (GlcN) in bone and joint disorders remainscontroversial. N-acetylation and other N-acylations of GlcN alter itsbiological properties fundamentally. N-butyryl glucosamine (GlcNBu)preserved strikingly the subchondral bone structure in a destructivearthritis rat model. Studies have shown that GlcNBu feeding in the OVXrat preserves bone mineral and some biomechanical properties(Anastassiades, T. et al., Translational Research, 2013, 162(2):93-101). Pharmaceutical applications of GlcNBu have also beendescribed (see for example, U.S. Pat. No. 6,479,469 (titled “Treatmentof Arthritis and Compositions Therefore”), and U.S. Patent ApplicationPublication No. 2006/0046976 (titled “Method for Increasing the BoneMineral Density and Bone Micro-architecture or Connectivity of a Mammalusing N-acylated Glucosamines), the contents of which are herebyincorporated by reference in their entirety.

However glucosamine and GlcNBu have limited therapeutic potential due totheir poor pharmacokinetic properties. Glucosamine is usuallyadministered in large doses (e.g., 3 g/day; see Barclay, T. S. et al.,The Annals of Pharmacotherapy, 1998, 32(5): 574-579) due to its low oralbioavailability (F) as assessed using rats (F: 0.19-0.21;Aghazadeh-Habashi, A. et al.; J. Pharm. Pharm. Sci., 2002, 5:181-4).When glucosamine is given even in very large doses to humans, it iscleared quickly from the circulation to the point that serum levelscannot be detected after oral or IV administration. N-acetylglucosamine(GluNAc) has a longer half-life than glucosamine when administered tohumans in polyvalent or monovalent form (Talent J. M. & Gracy R. W.,Clinical therapeutics 1996, 18: 1184-90), but no efficacy data wererecorded. GlcNBu also demonstrates low bioavailability, with an oralbioavailability range from 15% to 17% in Sprague Dawley (SD) rats. Inaddition to low bioavailability, GlcNBu is cleared quickly, with ahalf-life of only about 20 min. in rats (data from i.v., i.p., and p.o.studies; Aghazadeh-Habashi A. et al., Journal of Pharmacy &Pharmaceutical Sciences 2006, 9(3): 359-364).

SUMMARY

It is an object of the present invention to ameliorate at least some ofthe deficiencies present in the prior art. Embodiments of the presenttechnology have been developed based at least in part on the inventors'appreciation that there is a need for treatments for bone and jointdisorders such as osteoporosis and arthritis. These and other needs canbe satisfied by the disclosure herein of GlcNBu derivatives and/orprodrugs, pharmaceutical compositions and uses thereof to treatosteoporosis, arthritis, and other bone and joint disorders.

In a first broad aspect, there are provided compounds of Formula A, orpharmaceutically acceptable salts or esters thereof:

where X is O, N, or S; n is an integer from 1 to 6; R is a substitutedor unsubstituted C₂ to C₁₈ substituent selected from linear or branchedalkyl, alkenyl, alkynyl, aryl, heteroaryl, arylalkyl, alkylaryl,cycloalkyl, and alkyl comprising a cyclic or a heterocyclic moiety; R²is hydrogen, acyl, or alkyl; R¹, R³, R⁴, and R⁵ are independentlyhydrogen, substituted or unsubstituted alkyl, aryl, arylalkyl,alkylaryl, cyclic or heterocyclic moiety, or acyl group derived from acarboxylic acid, an amino acid, or a peptide, optionally with aprotecting group, a phosphonyl group, or a sulfonyl group, provided thatR¹, R³, R⁴, and R⁵ are not all hydrogen at the same time.

In one embodiment, R³ and R⁴, taken together with the atoms to whichthey are attached, form a substituted or unsubstituted heterocyclicring.

In another embodiment, R⁴ and R⁵, together with the atoms to which theyare attached, form a substituted or unsubstituted heterocyclic ring.

In one embodiment, one or more of R¹, R³, R⁴, and R⁵ are independentlyin the form of Q¹C(═O)—, where Q¹ is selected from unsubstituted orsubstituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, carbocyclic groupwith or without a substituent group, heterocyclic group with or withouta substituent group, alkoxy, aryloxy, arylalkyloxy, and alkylaryloxy;and an amino or hydroxyl group in Q¹, if present, may or may not befurther substituted.

In another embodiment, one or more of R¹, R³, R⁴, and R⁵ areindependently selected from alkoxycarbonyl, aryloxycarbonyl, andarylalkoxycarbonyl.

In an embodiment, R is a substituted or unsubstituted C₂ to C₁₂substituent selected from linear or branched alkyl, alkenyl, alkynyl,aryl, heteroaryl, arylalkyl, alkylaryl, cycloalkyl, and alkyl comprisinga cyclic or a heterocyclic moiety.

In one embodiment, a compound according to Formula (A) is inalpha-configuration at the anomeric center; in another embodiment, acompound according to Formula (A) is in beta-configuration at theanomeric center; and in a further embodiment, a compound according toFormula (A) is a mixture of alpha- and beta-configuration at theanomeric center.

In some embodiments, n is 1 to 4; in another embodiment, n is 2; in afurther embodiment, n is 1.

In another aspect, there are provided compounds of Formula (I), orpharmaceutically acceptable salts or esters thereof:

where R, R¹ through R⁵, and n are as previously defined.

In one embodiment, a compound according to Formula (I) is inalpha-configuration at the anomeric center; in another embodiment, acompound according to Formula (I) is in beta-configuration at theanomeric center; and in a further embodiment, a compound according toFormula (I) is a mixture of alpha- and beta-configuration at theanomeric center.

In some embodiments of Formula (I), n is 1 to 4; in an embodiment, n is2; and in another embodiment, n is 1.

In an embodiment of Formula (I), R² is hydrogen.

In another aspect, there are provided compounds of Formula (II), orpharmaceutically acceptable salts or esters thereof:

where R¹ through R⁵ and n are as previously defined.

In one embodiment, a compound according to Formula (II) is inalpha-configuration at the anomeric center; in another embodiment, acompound according to Formula (II) is in beta-configuration at theanomeric center; and in a further embodiment, a compound according toFormula (II) is a mixture of alpha- and beta-configuration at theanomeric center.

In some embodiments of Formula (II), n is 1 to 4; in an embodiment, n is2; and in another embodiment, n is 1.

In an embodiment of Formula (II), R² is hydrogen.

In another aspect, there are provided compounds of Formula (III), orpharmaceutically acceptable salts or esters thereof:

where R¹, R³ through R⁵ and n are as previously defined.

In another aspect, there are provided compounds of Formula (IV), orpharmaceutically acceptable salts or esters thereof:

where R¹ and R³ through R⁵ are as previously defined.

In one embodiment of Formula (IV), R¹, R³, R⁴, and R⁵ are independentlyH, C₁-C₁₂ alkyl, acyl, or an amino acid residue, provided that R¹, R³,R⁴, and R⁵ are not all H at the same time.

In another embodiment of Formula (IV), R¹ is H, and R³, R⁴, and R⁵ areindependently H, C₁-C₆ alkyl, acyl, or a natural amino acid residue,provided that R³, R⁴, and R⁵ are not all H at the same time.

In another embodiment of Formula (IV), R¹ and R³ are H, and R⁴ and R⁵are independently selected from H, C₁-C₆ acyl, or an unsubstituted orsubstituted natural amino acyl group.

In one embodiment, a compound according to Formula (IV) is inalpha-configuration at the anomeric center; in another embodiment, acompound according to Formula (IV) is in beta-configuration at theanomeric center; and in a further embodiment, a compound according toFormula (IV) is a mixture of alpha- and beta-configuration at theanomeric center.

In another embodiment of compounds provided herein, R² is hydrogen (H).

In some embodiments, the compound of Formula (A), (I), (II), (III), or(IV) is not a derivative of N-acetyl glucosamine.

In one embodiment, the C, H, O, and/or N atoms in the compound ofFormula (A), (I), (II), (III), or (IV) are in natural abundance or areisotope-enriched.

In another embodiment, the C atoms in the compound of Formula (A), (I),(II), (III), or (IV) are independently ¹²C, ¹³C, or ¹⁴C; the H atoms areindependently ¹H, D (²H), or T (³H); the O-atoms are independently ¹⁶O,¹⁷O, or ¹⁸O; and the N atoms are independently ¹⁴N or ¹⁵N.

In some embodiments, at least one of the C, H, O and N atoms in thecompound of Formula (A), (I), (II), (III), or (IV) is isotope-enriched.

In some embodiments, the compound of Formula (A), (I), (II), (III), or(IV) is a prodrug of GlcNBu. Without wishing to be limited by theory, insome cases the compound of Formula (A), (I), (II), (III), or (IV) may beconverted to GlcNBu in vivo after administration in a subject, and thusserve as a prodrug of GlcNBu. In such embodiments the compound ofFormula (A), (I), (II), (III), or (IV) may be used to increase thetherapeutic efficacy of GlcNBu in the treatment of bone and jointdisorders such as osteoporosis and/or arthritis by e.g. increasingbioavailability, stability, and/or reducing metabolism of GlcNBu, ascompared to administration of GlcNBu itself.

In some embodiments, the compound of Formula (A), (I), (II), (III), or(IV) is a compound shown in Table 1, or a pharmaceutically-acceptablesalt, ester, chelator, hydrate, solvate, stereoisomer, or polymorphicform thereof.

TABLE 1 Examples of GlcNBu derivatives. No. Structure 1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

In some embodiments, the compound of Formula (A), (I), (II), (III), or(IV) is a compound shown in Table 2, or a pharmaceutically-acceptablesalt, ester, chelator, hydrate, solvate, stereoisomer, or polymorphicform thereof.

TABLE 2 Other examples of GlcNBu derivatives. No. Structure 26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

In some embodiments, the compound of Formula (A), (I), (II), (III), or(IV) is a compound shown in Table 3, or a pharmaceutically-acceptablesalt, ester, chelator, hydrate, solvate, stereoisomer, or polymorphicform thereof.

TABLE 3 Further examples of GlcNBu derivatives. No. Structure 72

73

74

75

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

93

94

95

96

97

98

99

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

In a second broad aspect, there are provided pharmaceutical compositionscomprising a compound described herein, or a pharmaceutically acceptablesalt thereof, and a pharmaceutically acceptable carrier. In someembodiments, there are provided pharmaceutical compositions comprising acompound of any one of Formulae (A), and (I) to (IV), or apharmaceutically acceptable salt thereof, and a pharmaceuticallyacceptable carrier. In some embodiments, there are providedpharmaceutical compositions comprising a compound of any one of Formulae(A), and (I) to (IV), or a pharmaceutically acceptable salt thereof,wherein the compound is not a derivative of N-acetyl glucosamine.

In a third broad aspect, there are provided methods of preventing ortreating a bone or joint disease or disorder in a subject in needthereof comprising administering to the subject an effective amount of acompound and/or a pharmaceutical composition described herein. In oneembodiment, the bone or joint disease is osteoporosis. In oneembodiment, the bone or joint disease is arthritis. Non-limitingexamples of bone or joint diseases and disorders that may be treatedaccording to methods provided herein include osteoporosis, osteopenia,and arthritis, including osteoarthritis, inflammatory arthritis (e.g.,rheumatoid arthritis, psoriatic arthritis, etc.), traumatic arthritis,degenerative arthritis, dysplastic arthritis, and related conditions.

In some embodiments, compounds of Formulae (A), and (I) to (IV) and/orpharmaceutical compositions thereof are administered to increase thetherapeutic effectiveness of GlcNBu in a subject, as compared toadministration of GlcNBu.

In some embodiments, compounds of Formulae (A), and (I) to (IV) and/orpharmaceutical compositions thereof are administered to increase thebioavailability of GlcNBu, the AUC of GlcNBu in blood or plasma, theC_(max) of GlcNBu, the T_(max) of GlcNBu, the t_(1/2) of GlcNBu, thetherapeutic bio-distribution of GlcNBu, and/or the bioabsorption ofGlcNBu in a subject, as compared to administration of GlcNBu itself.

In some embodiments, the effective therapeutic level of GlcNBu in aselected tissue of a subject is increased after administration of acompound of any of Formulae (A), and (I) to (IV) and/or a pharmaceuticalcomposition thereof, as compared to administration of GlcNBu itself.

In some embodiments, compounds of Formulae (A), and (I) to (IV) and/orpharmaceutical compositions thereof are administered to reduce themetabolism of GlcNBu in a subject, as compared to administration ofGlcNBu itself.

In some embodiments, compounds of Formulae (A), and (I) to (IV) and/orpharmaceutical compositions thereof are administered to reduce the sideeffects of GlcNBu in a subject, as compared to administration of GlcNBuitself.

In some embodiments, compounds of Formulae (A), and (I) to (IV) and/orpharmaceutical compositions thereof are administered to enhancecartilage formation in a subject.

In some embodiments, compounds of Formulae (A), and (I) to (IV) and/orpharmaceutical compositions thereof are administered to enhancechondrocyte cell proliferation or growth in a subject.

In some embodiments, compounds of Formulae (A), and (I) to (IV) and/orpharmaceutical compositions thereof are administered to alleviate thesymptoms of joint stiffness and/or restricted mobility in a subject.

In some embodiments, compounds of Formulae (A), and (I) to (IV) and/orpharmaceutical compositions thereof are administered to enhance theproduction of glycosaminoglycan in a subject.

In some embodiments, compounds of Formulae (A), and (I) to (IV) and/orpharmaceutical compositions thereof are administered to increase bonemineral density (BMD) in a subject.

In some embodiments, compounds of Formulae (A), and (I) to (IV) and/orpharmaceutical compositions thereof are administered to improve bonemicro-architecture and/or bone connectivity in a subject.

In some embodiments, compounds of Formulae (A), and (I) to (IV) and/orpharmaceutical compositions thereof are administered to treat low BMD ina subject.

In some embodiments, compounds of Formulae (A), and (I) to (IV) and/orpharmaceutical compositions thereof are administered to prevent ordiminish the risk of fractures in a subject.

In some embodiments, compounds of Formulae (A), and (I) to (IV) and/orpharmaceutical compositions thereof are administered to treat or preventbone fractures, e.g., low impact fractures and/or high impact factures,in a subject.

In another broad aspect, there are provided kits comprising one or morecompound or pharmaceutical composition described herein. A kit mayfurther comprise one or more additional therapeutic agents and/orinstructions, for example, instructions for using the kit to treat asubject having a bone or joint disorder such as osteoporosis orarthritis.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the invention and to show more clearly howit may be carried into effect, reference will now be made by way ofexample to the accompanying drawings, which illustrate aspects andfeatures according to embodiments of the present invention, and inwhich:

FIG. 1 shows mean plasma GLcNBu concentration versus time curvesfollowing oral administration of GlcNBu and Compound 16 at a dose of0.93 mmol/kg.

FIGS. 2A-2B show comparison of mean plasma GLcNBu concentration versustime curves following oral administration of Compounds 5, 6, 12, 14, and18 (2A) and 41, 80, and 88 (2B) at a dose of 0.93 mmol/kg.

FIG. 3 shows mean plasma concentration versus time curves of GLcNBufollowing different routes of administration, as indicated (i.v., i.p.,and p.o., respectively). The insert is the enlarged curve following oraladministration (J. Pharm. Pharmaceut. Sci., 9 (3): 359-364, 2006).

FIGS. 4A-4H show various histological parameters obtained in a MIA ratmodel for osteoarthritis for control animals (G1) and animals treatedwith compound 16 at 234 mg/kg (G2) or 468 mg/kg (G3), as follows: 4A:Nature of predominant tissue, 4B: Surface regularity, 4C: Chondrocyteclustering, 4D: Structural integrity, 4E: Degenerative changes incartilage, 4F: Inflammatory response in subchondral bone region, 4G:Neo-vascularization, and 4H: Osteophytes.

FIG. 5 shows weight bearing results for rats in a MMT model treated withcompound 16 (G2) or vehicle (G1); *: Vs G1, P<0.05; **: Vs G1, P<0.01.

FIGS. 6A-6I show various histological parameters obtained in a MMT ratmodel for osteoarthritis for control animals (G1) and animals treatedwith compound 16 (G2), as follows: 6A: Nature of predominant tissue; 6B:Surface regularity; 6C: Structural integrity; 6D: Chondrocyte clustering(*: Vs G1, P<0.05); 6E: Degenerative changes in cartilage; 6F:Inflammatory response in subchondral bone region; 6G:Neo-vascularization; 6H: Osteophytes; and 6I: Total scoring.

DETAILED DESCRIPTION Definitions

In order to provide a clear and consistent understanding of the termsused in the present specification, a number of definitions are providedbelow. Moreover, unless defined otherwise, all technical and scientificterms as used herein have the same meaning as commonly understood to oneof ordinary skill in the art to which this invention pertains.

The use of the word “a” or “an” when used in conjunction with the term“comprising” in the claims and/or the specification may mean “one”, butit is also consistent with the meaning of “one or more”, “at least one”,and “one or more than one”. Similarly, the word “another” may mean atleast a second or more.

As used in this specification and claim(s), the words “comprising” (andany form of comprising, such as “comprise” and “comprises”), “having”(and any form of having, such as “have” and “has”), “including” (and anyform of including, such as “include” and “includes”) or “containing”(and any form of containing, such as “contain” and “contains”), areinclusive or open-ended and do not exclude additional, unrecitedelements or process steps.

The term “about” is used to indicate that a value includes an inherentvariation of error for the device or the method being employed todetermine the value.

The term “derivative” as used herein, is understood as being a substancesimilar in structure to another compound but differing in some slightstructural detail.

The present description refers to a number of chemical terms andabbreviations used by those skilled in the art. Nevertheless,definitions of selected terms are provided for clarity and consistency.

As used herein, the term “alkyl” refers to saturated hydrocarbons havingfrom one to twelve carbon atoms, including linear, branched, and cyclicalkyl groups. Examples of alkyl groups include, without limitation,methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl,decyl, isopropyl, tert-butyl, sec-butyl, isobutyl, cyclopropyl,cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and the like. The termalkyl includes both unsubstituted alkyl groups and substituted alkylgroups. The term “C₁-C_(n)alkyl”, wherein n is an integer from 2 to 12,refers to an alkyl group having from 1 to the indicated “n” number ofcarbon atoms. Alkyl residues may be substituted or unsubstituted. Insome embodiments, for example, alkyl may be substituted by hydroxyl,amino, carboxyl, carboxylic ester, amide, carbamate, or aminoalkyl.

As used herein, the term “acyclic” refers to an organic moiety without aring system. The term “aliphatic group” includes organic moietiescharacterized by straight or branched-chains, typically having between 1and 15 carbon atoms. Aliphatic groups include non-cyclic alkyl groups,alkenyl groups, and alkynyl groups.

As used herein, the term “alkenyl” refers to unsaturated hydrocarbonshaving from two to twelve carbon atoms, including linear, branched, andcyclic non aromatic alkenyl groups, and comprising between one to sixcarbon-carbon double bonds. Examples of alkenyl groups include, withoutlimitation, vinyl, allyl, 1-propen-2-yl, 1-buten-3-yl, 1-buten-4-yl,2-buten-4-yl, 1-penten-5-yl, 1,3-pentadien-5-yl, cyclopentenyl,cyclohexenyl, ethylcyclopentenyl, ethylcylohexenyl, and the like. Theterm alkenyl includes both unsubstituted alkenyl groups and substitutedalkenyl groups. The term “C₂-C_(n)alkenyl”, wherein n is an integer from3 to 12, refers to an alkenyl group having from 2 to the indicated “n”number of carbon atoms.

As used herein, the term “alkynyl” refers to unsaturated hydrocarbonshaving from two to twelve carbon atoms, including linear, branched, andcyclic non aromatic alkynyl groups, and comprising between one to sixcarbon-carbon triple bonds. Examples of alkynyl groups include, withoutlimitation, ethynyl, 1-propyn-3-yl, 1-butyn-4-yl, 2-butyn-4-yl,1-pentyn-5-yl, 1,3-pentadiyn-5-yl, and the like. The term alkynylincludes both unsubstituted alkynyl groups and substituted alkynylgroups. The term “C₂-C_(n)alkynyl”, wherein n is an integer from 3 to12, refers to an alkynyl group having from 2 to the indicated “n” numberof carbon atoms.

Unless the number of carbons is otherwise specified, “lower” as in“lower aliphatic,” “lower alkyl,” “lower alkenyl,” and “lower alkylnyl”,as used herein means that the moiety has at least one (two for alkenyland alkynyl) and equal to or less than 6 carbon atoms.

The terms “cycloalkyl”, “alicyclic”, “carbocyclic” and equivalentexpressions refer to a group comprising a saturated or partiallyunsaturated carbocyclic ring in a single, spiro (sharing one atom), orfused (sharing at least one bond) carbocyclic ring system having fromthree to fifteen ring members. Examples of cycloalkyl groups include,without limitation, cyclopropyl, cyclobutyl, cyclopentyl,cyclopenten-1-yl, cyclopenten-2-yl, cyclopenten-3-yl, cyclohexyl,cyclohexen-1-yl, cyclohexen-2-yl, cyclohexen-3-yl, cycloheptyl,bicyclo[4,3,0]nonanyl, norbornyl, and the like. The term cycloalkylincludes both unsubstituted cycloalkyl groups and substituted cycloalkylgroups. The term “C₃-C_(n)cycloalkyl”, wherein n is an integer from 4 to15, refers to a cycloalkyl group having from 3 to the indicated “n”number of carbon atoms in the ring structure. Unless the number ofcarbons is otherwise specified, “lower cycloalkyl” groups as hereinused, have at least 3 and equal to or less than 8 carbon atoms in theirring structure.

Cycloalkyl residues can be saturated or contain one or more double bondswithin the ring system. In particular they can be saturated or containone double bond within the ring system. In unsaturated cycloalkylresidues the double bonds can be present in any suitable positions.Monocycloalkyl residues are, for example, cyclopropyl, cyclobutyl,cyclopentyl, cyclopentenyl, cyclohexyl, cyclohexenyl, cycloheptyl,cycloheptenyl, cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl,cyclododecyl or cyclotetradecyl, which can also be substituted, forexample by C₁₋₄ alkyl. Examples of substituted cycloalkyl residues are4-methylcyclohexyl and 2,3-dimethylcyclopentyl. Examples of parentstructures of bicyclic ring systems are norbornane,bicyclo[2.2.1]heptane, bicyclo[2.2.2]octaneandbicyclo[3.2.1]octane.

The term “heterocycloalkyl” and equivalent expressions refer to a groupcomprising a saturated or partially unsaturated carbocyclic ring in asingle, spiro (sharing one atom), or fused (sharing at least one bond)carbocyclic ring system having from three to fifteen ring members,including one to six heteroatoms (e.g., N, O, S, P) or groups containingsuch heteroatoms (e.g., NH, NR_(x) (R_(x) is alkyl, acyl, aryl,heteroaryl or cycloalkyl), PO₂, SO, SO₂, and the like). Heterocycloalkylgroups may be C-attached or heteroatom-attached (e.g., via a nitrogenatom) where such is possible. Examples of heterocycloalkyl groupsinclude, without limitation, pyrrolidino, tetrahydrofuranyl,tetrahydrodithienyl, tetrahydropyranyl, tetrahydrothiopyranyl,piperidino, morpholino, thiomorpholino, thioxanyl, piperazinyl,azetidinyl, oxetanyl, thietanyl, homopiperidinyl, oxepanyl, thiepanyl,oxazepinyl, diazepinyl, thiazepinyl, 1,2,3,6-tetrahydropyridinyl,2-pyrrolinyl, 3-pyrrolinyl, indolinyl, 2H-pyranyl, 4H-pyranyl, dioxanyl,1,3-dioxolanyl, pyrazolinyl, dithianyl, dithiolanyl, dihydropyranyl,dihydrothienyl, dihydrofuranyl, pyrazolidinyl, imidazolinyl,imidazolidinyl, 3-azabicyclo[3,1,0]hexanyl, 3-azabicyclo[4,1,0]heptanyl,3H-indolyl, quinolizinyl, and sugars, and the like. The termheterocycloalkyl includes both unsubstituted heterocycloalkyl groups andsubstituted heterocycloalkyl groups. The term“C₃-C_(n)heterocycloalkyl”, wherein n is an integer from 4 to 15, refersto a heterocycloalkyl group having from 3 to the indicated “n” number ofatoms in the ring structure, including at least one hetero group or atomas defined above. Unless the number of carbons is otherwise specified,“lower heterocycloalkyl” groups as herein used, have at least 3 andequal to or less than 8 carbon atoms in their ring structure.

The terms “aryl” and “aryl ring” refer to aromatic groups having“4n+2”.pi.(pi) electrons, wherein n is an integer from 1 to 3, in aconjugated monocyclic or polycyclic system (fused or not) and having sixto fourteen ring atoms. A polycyclic ring system includes at least onearomatic ring. Aryl may be directly attached, or connected via aC₁-C₃alkyl group (also referred to as arylalkyl or aralkyl). Examples ofaryl groups include, without limitation, phenyl, benzyl, phenetyl,1-phenylethyl, tolyl, naphthyl, biphenyl, terphenyl, indenyl,benzocyclooctenyl, benzocycloheptenyl, azulenyl, acenaphthylenyl,fluorenyl, phenanthernyl, anthracenyl, and the like. The term arylincludes both unsubstituted aryl groups and substituted aryl groups. Theterm “C₆-C_(n)aryl”, wherein n is an integer from 6 to 15, refers to anaryl group having from 6 to the indicated “n” number of atoms in thering structure, including at least one hetero group or atom as definedabove.

The terms “heteroaryl” and “heteroaryl ring” refer to an aromatic groupshaving “4n+2”.pi.(pi) electrons, wherein n is an integer from 1 to 3, ina conjugated monocyclic or polycyclic system (fused or not) and havingfive to fourteen ring members, including one to six heteroatoms (e.g. N,O, S) or groups containing such heteroatoms (e.g. NH, NR_(x) (R_(x) isalkyl, acyl, aryl, heteroaryl or cycloalkyl), SO, and the like). Apolycyclic ring system includes at least one heteroaromatic ring.Heteroaryls may be directly attached, or connected via a C₁-C₃alkylgroup (also referred to as heteroarylalkyl or heteroaralkyl). Heteroarylgroups may be C-attached or heteroatom-attached (e.g., via a nitrogenatom), where such is possible. Examples of heteroaryl groups include,without limitation, pyridyl, imidazolyl, pyrimidinyl, pyrazolyl,triazolyl, tetrazolyl, furyl, thienyl; isooxazolyl, thiazolyl, oxazolyl,isothiazolyl, pyrrollyl, quinolinyl, isoquinolinyl, indolyl, isoindolyl,chromenyl, isochromenyl, benzimidazolyl, benzofuranyl, cinnolinyl,indazolyl, indolizinyl, phthalazinyl, pyridazinyl, pyrazinyl, triazinyl,isoindolyl, pteridinyl, purinyl, oxadiazolyl, thiadiazolyl, furazanyl,benzofurazanyl, benzothiophenyl, benzothienyl, benzothiazolyl,benzoxazolyl, quinazolinyl, quinolizinyl, quinolonyl, isoquinolonyl,quinoxalinyl, naphthyridinyl, furopyridinyl, carbazolyl,phenanthridinyl, acridinyl, perimidinyl, phenanthrolinyl, phenazinyl,phenothiazinyl, phenoxazinyl, dibenzofurnayl, and the like. The termheteroaryl includes both unsubstituted heteroaryl groups and substitutedheteroaryl groups. The term “C₅-C_(n)heteroaryl”, wherein n is aninteger from 6 to 15, refers to a heteroaryl group having from 5 to theindicated “n” number of atoms in the ring structure, including at leastone hetero group or atom as defined above.

The terms “heterocycle” or “heterocyclic” include heterocycloalkyl andheteroaryl groups. Examples of heterocycles include, without limitation,acridinyl, azocinyl, benzimidazolyl, benzofuranyl, benzothiofuranyl,benzothiophenyl, benzoxazolyl, benzthiazolyl, benztriazolyl,benztetrazolyl, benzisoxazolyl, benzisothiazolyl, benzimidazolinyl,carbazolyl, 4αH-carbazolyl, carbolinyl, chromanyl, chromenyl,cinnolinyl, decahydroquinolinyl, 2H,6H-1,5,2-dithiazinyl,dihydrofuro[2,3-b]tetrahydrofuran, furanyl, furazanyl, imidazolidinyl,imidazolinyl, imidazolyl, 1H-indazolyl, indolenyl, indolinyl,indolizinyl, indolyl, 3H-indolyl, isobenzofuranyl, isochromanyl,isoindazolyl, isoindolinyl, isoindolyl, isoquinolinyl, isothiazolyl,isoxazolyl, methylenedioxyphenyl, morpholinyl, naphthyridinyl,octahydroisoquinolinyl, oxadiazolyl, 1,2,3-oxadiazolyl,1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl, 1,3,4-oxadiazolyl, oxazolidinyl,oxazolyl, oxazolidinyl, pyrimidinyl, phenanthridinyl, phenanthrolinyl,phenazinyl, phenothiazinyl, phenoxathiinyl, phenoxazinyl, phthalazinyl,piperazinyl, piperidinyl, piperidonyl, 4-piperidonyl, piperonyl,pteridinyl, purinyl, pyranyl, pyrazinyl, pyrazolidinyl, pyrazolinyl,pyrazolyl, pyridazinyl, pyridooxazole, pyridoimidazole, pyridothiazole,pyridinyl, pyridyl, pyrimidinyl, pyrrolidinyl, pyrrolinyl, 2H-pyrrolyl,pyrrolyl, quinazolinyl, quinolinyl, 4H-quinolizinyl, quinoxalinyl,quinuclidinyl, tetrahydrofuranyl, tetrahydroisoquinolinyl,tetrahydroquinolinyl, tetrazolyl, 6H-1,2,5-thiadiazinyl,1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl, 1,2,5-thiadiazolyl,1,3,4-thiadiazolyl, thianthrenyl, thiazolyl, thienyl, thienothiazolyl,thienooxazolyl, thienoimidazolyl, thiophenyl, triazinyl,1,2,3-triazolyl, 1,2,4-triazolyl, 1,2,5-triazolyl, 1,3,4-triazolyl,xanthenyl, and the like. The term heterocycle includes bothunsubstituted heterocyclic groups and substituted heterocyclic groups.

The term “amine” or “amino,” as used herein, refers to an unsubstitutedor substituted moiety of the formula —NR^(a)R^(b), in which R^(a) andR^(b) are each independently hydrogen, alkyl, aryl, or heterocyclyl, orR^(a) and R^(b), taken together with the nitrogen atom to which they areattached, form a heterocyclic ring. The term amino includes compounds ormoieties in which a nitrogen atom is covalently bonded to at least onecarbon or heteroatom. Thus, the terms “alkylamino” and “dialkylamino” asused herein mean an amine group having respectively one and at least twoC₁-C₆alkyl groups attached thereto. The terms “arylamino” and“diarylamino” include groups wherein the nitrogen is bound to at leastone or two aryl groups, respectively. The terms “amide” or“aminocarbonyl” include compounds or moieties which contain a nitrogenatom which is bound to the carbon of a carbonyl or a thiocarbonyl group.The term “acylamino” refers to an amino group directly attached to anacyl group as defined herein.

The term “nitro” means —NO₂; the terms “halo” and “halogen” refer tobromine, chlorine, fluorine or iodine substituents; the terms “thiol”,“thio”, or “mercapto” mean SH; and the terms “hydroxyl” or “hydroxy”mean —OH. The term “alkylthio” refers to an alkyl group, having asulfhydryl group attached thereto. Suitable alkylthio groups includegroups having 1 to about 12 carbon atoms, preferably from 1 to about 6carbon atoms. The term “alkylcarboxyl” as used herein means an alkylgroup having a carboxyl group attached thereto.

The terms “alkoxy” or “lower alkoxy” as used herein mean an alkyl grouphaving an oxygen atom attached thereto. Representative alkoxy groupsinclude groups having 1 to about 6 carbon atoms, e.g., methoxy, ethoxy,propoxy, tert-butoxy and the like. Examples of alkoxy groups includemethoxy, ethoxy, isopropyloxy, propoxy, butoxy, pentoxy, fluoromethoxy,difluoromethoxy, trifluoromethoxy, chloromethoxy, dichloromethoxy,trichloromethoxy groups, and the like. The term “alkoxy” includes bothunsubstituted or substituted alkoxy groups, etc., as well asperhalogenated alkyloxy groups.

The terms “carbonyl” or “carboxy” include compounds and moieties whichcontain a carbon connected with a double bond to an oxygen atom.Examples of moieties which contain a carbonyl include aldehydes,ketones, carboxylic acids, amides, esters, anhydrides, etc.

The term “acyl” refers to a carbonyl group that is attached through itscarbon atom to a hydrogen (i.e., formyl), an aliphatic group(C₁-C₆alkyl, C₁-C₆alkenyl, C₁-C₆alkynyl, e.g., acetyl), a cycloalkylgroup (C₃-C₈cycloalkyl), a heterocyclic group (C₃-C₈heterocycloalkyl andC₅-C₆heteroaryl), an aromatic group (C₆aryl, e.g., benzoyl), and thelike. Acyl groups may be unsubstituted or substituted acyl groups (e.g.,salicyloyl).

It should be understood that “substitution” or “substituted with”includes the implicit proviso that such substitution is in accordancewith the permitted valence of the substituted atom and the substituent,and that the substitution results in a stable compound, i.e., a compoundwhich does not spontaneously undergo transformation such as byrearrangement, cyclization, elimination, etc. As used herein, the term“substituted” is meant to include all permissible substituents oforganic compounds. In a broad aspect, the permissible substituentsinclude acyclic and cyclic, branched and unbranched, carbocyclic andheterocyclic, aromatic and nonaromatic substituents of organiccompounds. The permissible substituents can be one or more. The term“substituted”, when in association with any of the foregoing groupsrefers to a group substituted at one or more position with substituentssuch as acyl, amino (including simple amino, mono and dialkylamino, monoand diarylamino, and alkylarylamino), acylamino (including carbamoyl,and ureido), alkylcarbonyloxy, arylcarbonyloxy, alkoxycarbonyloxy,alkoxycarbonyl, carboxy, carboxylate, aminocarbonyl, mono anddialkylaminocarbonyl, cyano, azido, halogen, hydroxyl, nitro,trifluoromethyl, thio, alkylthio, arylthio, alkylthiocarbonyl,thiocarboxylate, lower alkyl, lower alkenyl, lower alkynyl, cycloalkyl,heterocycloalkyl, aryl, heteroaryl, lower alkoxy, aryloxy,aryloxycarbonyloxy, benzyloxy, benzyl, sulfinyl, alkylsulfinyl,sulfonyl, sulfate, sulfonate, sulfonamide, phosphate, phosphonato,phosphinato, oxo, guanidine, imino, formyl and the like. Any of theabove substituents can be further substituted if permissible, e.g., ifthe group contains an alkyl group, an aryl group, or other.

The term “solvate” refers to a physical association of a compound withone or more solvent molecules, whether organic or inorganic. Thisphysical association includes hydrogen bonding. In certain instances, asolvate will be capable of isolation, for example when one or moresolvent molecules are incorporated in the crystal lattice of acrystalline solid. “Solvate” encompasses both solution-phase andisolable solvates. Exemplary solvates include, without limitation,hydrates, ethanolates, methanolates, hemiethanolates, and the like.

Isotopic enrichment is a process by which the relative abundance of theisotopes of a given element are altered, thus producing a form of theelement that has been enriched (i.e., increased) in one particularisotope and reduced or depleted in its other isotopic forms. As usedherein, an “isotope-enriched” compound or derivative refers to acompound in which one or more specific isotopic form has been increased,i.e., one or more of the elements has been enriched (i.e., increased) inone or more particular isotope. Generally, in an isotope-enrichedcompound or derivative, a specific isotopic form of an element at aspecific position of the compound is increased. It should be understoodhowever that isotopic forms of two or more elements in the compound maybe increased. Further, an isotope-enriched compound may be a mixture ofisotope-enriched forms that are enriched for more than one particularisotope, more than one element, or both.

Under normal conditions, the natural abundances for deuterium (D or 2H)(a stable isotope of hydrogen with a mass approximately twice that ofthe usual isotope), nitrogen-15 (¹⁵N), carbon-13 (¹³C), oxygen-18 (¹⁸O),and oxygen-7 (¹⁷O) are 0.016%, 0.37%, 1.11%, 0.204%, and 0.037%,respectively. As used herein, an “isotope-enriched” compound orderivative possesses a level of an isotopic form that is higher than thenatural abundance of that form. The level of isotope-enrichment willvary depending on the natural abundance of a specific isotopic form. Insome embodiments, the level of isotope-enrichment for a compound, or foran element in a compound, may be from about 2 to about 100 molar percent(%), e.g., about 2%, about 5%, about 17%, about 30%, about 51%, about83%, about 90%, about 95%, about 96%, about 97%, about 98%, greater thanabout 98%, about 99%, or 100%. In one embodiment, the level ofisotope-enrichment in an isotope-enriched compound of the invention (acompound of any one of Formula (A), (I), (II), (III), or (IV), etc.) isabout 5% or higher, or about 10% or higher. In another embodiment, thelevel of isotope-enrichment in an isotope-enriched compound of theinvention is about 20% or higher, or about 50% or higher. In yet anotherembodiment, the level of isotope-enrichment in an isotope-enrichedcompound of the invention is about 75% or higher, or about 90% orhigher. In still another embodiment, the level of isotope-enrichment inan isotope-enriched compound of the invention is about 95% or higher, or100%. It should be understood that the level of isotope-enrichment for aparticular compound, or a particular element of a compound, will beselected based on several properties of the compound such as itschemical, pharmacokinetic, and therapeutic profiles, with the aim ofimproving the compound's therapeutic efficacy, therapeuticbio-distribution, bioavailability, metabolism, stability, and/orpharmacokinetic profile.

As used herein, an “element of natural abundance” and an “atom ofnatural abundance” refers to the element or atom respectively having theatomic mass most abundantly found in nature. For example, hydrogen ofnatural abundance is ¹H (protium); nitrogen of natural abundance is ¹⁴N;oxygen of natural abundance is ¹⁶O; carbon of natural abundance is ¹²C;and so on. A “non-isotope enriched” compound is a compound in which allthe atoms or elements in the compound are isotopes of natural abundance,i.e., all the atoms or elements have the atomic mass most abundantlyfound in nature. This is in contrast to an isotope-enriched compound inwhich one or more element is enriched for one or more specific isotopicform that is not the isotope of natural abundance.

As used herein, “D” refers to deuterium (²H) and “T” refers to tritium(³H).

A “pharmaceutically acceptable salt” of a compound means a salt of acompound that is pharmaceutically acceptable. Desirable are salts of acompound that retain or improve the biological effectiveness andproperties of the free acids and bases of the parent compound as definedherein or that take advantage of an intrinsically basic, acidic orcharged functionality on the molecule and that are not biologically orotherwise undesirable. Examples of pharmaceutically acceptable salts arealso described, for example, in Berge et al., “Pharmaceutical Salts”, J.Pharm. Sci. 66, 1-19 (1977). Non-limiting examples of such saltsinclude:

(1) acid addition salts, formed on a basic or positively chargedfunctionality, by the addition of inorganic acids such as hydrochloricacid, hydrobromic acid, hydroiodic acid, sulfuric acid, sulfamic acid,nitric acid, phosphoric acid, carbonate forming agents, and the like; orformed with organic acids such as acetic acid, propionic acid, lacticacid, oxalic, glycolic acid, pivalic acid, t-butylacetic acid,O-hydroxybutyric acid, valeric acid, hexanoic acid,cyclopentanepropionic acid, pyruvic acid, malonic acid, succinic acid,malic acid, maleic acid, fumaric acid, tartaric acid, citric acid,benzoic acid, 3-(4-hydroxybenzoyl)benzoic acid, cinnamic acid, mandelicacid, methanesulfonic acid, ethanesulfonic acid, 1,2-ethanedisulfonicacid, 2-hydroxyethanesulfonic acid, cyclohexylaminosulfonic acid,benzenesulfonic acid, sulfanilic acid, 4-chlorobenzenesulfonic acid,2-napthalenesulfonic acid, 4-toluenesulfonic acid, camphorsulfonic acid,3-phenyl propionic acid, lauryl sulphonic acid, lauryl sulfuric acid,oleic acid, palmitic acid, stearic acid, lauric acid, embonic (pamoic)acid, palmoic acid, pantothenic acid, lactobionic acid, alginic acid,galactaric acid, galacturonic acid, gluconic acid, glucoheptonic acid,glutamic acid, naphthoic acid, hydroxynapthoic acid, salicylic acid,ascorbic acid, stearic acid, muconic acid, and the like;

(2) base addition salts, formed when an acidic proton present in theparent compound either is replaced by a metal ion, including, an alkalimetal ion (e.g., lithium, sodium, potassium), an alkaline earth ion(e.g., magnesium, calcium, barium), or other metal ions such asaluminum, zinc, iron and the like; or coordinates with an organic basesuch as ammonia, ethylamine, diethylamine, ethylenediamine,N,N′-dibenzylethylenediamine, ethanolamine, diethanolamine,triethanolamine, tromethamine, N-methylglucamine, piperazine,chloroprocain, procain, choline, lysine and the like.

Pharmaceutically acceptable salts may be synthesized from a parentcompound that contains a basic or acidic moiety, by conventionalchemical methods. Generally, such salts are prepared by reacting thefree acid or base forms of compounds with a stoichiometric amount of theappropriate base or acid in water or in an organic solvent, or in amixture of the two. Salts may be prepared in situ, during the finalisolation or purification of a compound or by separately reacting acompound in its free acid or base form with the desired correspondingbase or acid, and isolating the salt thus formed. The term“pharmaceutically acceptable salts” also include zwitterionic compoundscontaining a cationic group covalently bonded to an anionic group, asthey are “internal salts”. It should be understood that all acid, salt,base, and other ionic and non-ionic forms of compounds described hereinare intended to be encompassed. For example, if a compound is shown asan acid herein, the salt forms of the compound are also encompassed.Likewise, if a compound is shown as a salt, the acid and/or basic formsare also encompassed.

As used herein, “AUC” refers to the area under a curve representing theconcentration of a compound in a biological sample from a subject as afunction of time following administration of the compound to thesubject. Non-limiting examples of such biological samples includebiological fluids such as plasma, blood, cerebrospinal fluid (CSF), andsaliva; organ homogenates such as brain and liver homogenates; and thelike. The AUC can be determined by measuring the concentration of acompound in a biological sample such as the plasma, blood, CSF or brainhomogenate using methods such as liquid chromatography-tandem massspectrometry (LC/MS/MS), at various time intervals, and calculating thearea under the concentration-versus-time curve. Suitable methods forcalculating the AUC from a drug concentration-versus-time curve are wellknown in the art. As relevant to the disclosure here, an AUC for GlcNBucan be determined by measuring the concentration of GlcNBu in theplasma, blood, or tissue homogenate of a subject following oraladministration of a compound described herein to the subject.

“Bioavailability” refers to the rate and amount of a compound thatreaches the systemic circulation of a subject following administrationof the compound or a prodrug thereof to the subject and can bedetermined by evaluating, for example, the plasma or bloodconcentration-versus-time profile for the compound. Parameters useful incharacterizing a plasma or blood concentration-versus-time curve includethe area under the curve (AUC), the time to peak concentration(T_(max)), and the maximum compound concentration (C_(max)). “C_(max)”is the maximum concentration of a compound in the biological sample of asubject following administration of a dose of the compound to thesubject. “T_(max)” is the time to the maximum concentration (C_(max)) ofa compound in the biological sample of a subject followingadministration of a dose of the compound to the subject. “t_(1/2)” isthe terminal elimination half-life of a compound in the biologicalsample of a subject following administration of a dose of the compoundto the subject. Bioavailability is often expressed as F(%) referring tothe ratio in percentage of the AUC of the compound for a specific modeof administration (e.g., orally) over AUC of the compound afterintravenous (IV) administration.

“Bioequivalence” refers to equivalence of the rate and extent ofabsorption of a therapeutic agent, such as a compound, afteradministration of equal doses of the agent to a patient. As used herein,two plasma or blood concentration profiles are bioequivalent if the 90%confidence interval for the ratio of the mean response of the twoprofiles is within the limits of 0.8 and 1.25. The mean responseincludes at least one of the characteristic parameters of a profile suchas Cmax, Tmax, or AUC.

As used herein the term “effective amount” refers to the amount or doseof a therapeutic agent, such as a compound, upon single or multiple doseadministration to a subject, which provides the desired therapeutic,diagnostic, or prognostic effect in the subject. An effective amount canbe readily determined by an attending physician or diagnostician usingknown techniques and by observing results obtained under analogouscircumstances. In determining the effective amount or dose of compoundadministered, a number of factors are considered including, but notlimited to: the size, age, and general health of the subject; thespecific disease involved; the degree of or involvement or the severityof the disease or condition to be treated; the response of theindividual subject; the particular compound administered; the mode ofadministration; the bioavailability characteristics of the preparationadministered; the dose regimen selected; the use of concomitantmedication(s); and other relevant considerations.

“Pharmaceutically acceptable” refers to drugs, medicaments, inertingredients etc., which the term describes, suitable for use in contactwith the cells or tissues of humans and animals without undue toxicity,incompatibility, instability, irritation, allergic response, and thelike, commensurate with a reasonable benefit/risk ratio. It generallyrefers to a compound or composition that is approved or approvable by aregulatory agency of the Federal or state government or listed in theU.S. Pharmacopoeia or other generally recognized pharmacopoeia for usein animals and more particularly in humans.

“Pharmaceutically acceptable vehicle” refers to a diluent, adjuvant,excipient, vehicle or carrier with which a compound is administered. Theterms “Pharmaceutically acceptable vehicle” and “Pharmaceuticallyacceptable carrier” are used interchangeably herein.

“Pharmaceutical composition” refers to a composition comprising acompound as described herein and at least one component comprising apharmaceutically acceptable carrier, diluent, adjuvant, excipient, orvehicle, such as a preserving agent, a filler, a disintegrating agent, awetting agent, an emulsifying agent, a suspending agent, a sweeteningagent, a flavoring agent, a perfuming agent, an antibacterial agent, anantifungal agent, a lubricating agent, a dispensing agent, and the like,depending on the nature of the mode of administration and dosage forms.“Preventing” or “prevention” is intended to refer to at least thereduction of likelihood of the risk of (or susceptibility to) acquiringa disease or disorder (i.e., causing at least one of the clinicalsymptoms of the disease not to develop in a patient that may be exposedto or predisposed to the disease but does not yet experience or displaysymptoms of the disease).

“Treating” or “treatment” of any disease or disorder refers, in someembodiments, to ameliorating at least one disease or disorder (i.e.,arresting or reducing the development of the disease or at least one ofthe clinical symptoms thereof). In certain embodiments “treating” or“treatment” refers to ameliorating at least one physical parameter,which may or may not be discernible by the patient. In certainembodiments, “treating” or “treatment” refers to inhibiting the diseaseor disorder, either physically, (e.g., stabilization of a discerniblesymptom), physiologically, (e.g., stabilization of a physicalparameter), or both. In some embodiments, “treating” or “treatment”refers to improving the quality of life or reducing the symptoms or sideeffects of a bone or joint disorder such as osteoporosis or arthritis ina subject in need thereof. “Therapeutically effective amount” means theamount of a compound that, when administered to a subject for treatingor preventing a disease, is sufficient to effect such treatment orprevention of the disease. The “therapeutically effective amount” willvary depending on the compound, the disease and its severity, and theage, weight, etc., of the subject having the disease to be treated orprevented. As used herein, the term “therapeutically effective amount”refers to an amount of a compound or composition sufficient to prevent,treat, inhibit, reduce, ameliorate or eliminate one or more causes,symptoms, or complications of a bone or joint disease such asosteoporosis, osteopenia, or arthritis. In certain embodiments, adesired therapeutic effect is the attainment of one or more of thefollowing in a subject: enhanced cartilage formation; enhancedchondrocyte cell proliferation or growth; reduced joint stiffness;increased mobility, or reduction in restricted mobility; enhancedproduction of glycosaminoglycan; increased bone mineral density (BMD);improved bone micro-architecture and/or bone connectivity; and reducedrisk of fractures.

“Therapeutic effectiveness” means the ability of a compound orcomposition to provide a desired therapeutic effect. As used herein, theterm “increasing therapeutic effectiveness” refers to increasing thetherapeutic effect provided by a particular active therapeutic agent. Incertain embodiments “increasing therapeutic effectiveness” refers toimproving the pharmacokinetics of a therapeutic agent, e.g., attainingone or more target pharmacokinetic parameter, such that ability toattain a desired therapeutic effect with the therapeutic agent isimproved or increased. In some embodiments, “increasing therapeuticeffectiveness” means increasing one or more of the following:bioavailability of GlcNBu; AUC of GlcNBu in blood or plasma; C_(max) ofGlcNBu; T_(max) of GlcNBu; t_(1/2) of GlcNBu; bio-distribution ofGlcNBu; level of GlcNBu in a selected tissue; and/or bioabsorption ofGlcNBu; in a subject, as compared to administration of GlcNBu itself. Insome embodiments, “increasing therapeutic effectiveness” meansdecreasing one or more of the following: metabolism of GlcNBu; and sideeffects of GlcNBu; in a subject, as compared to administration of GlcNBuitself. In some embodiments, “increasing therapeutic effectiveness”means that the dose and/or dosing frequency of a compound or compositionsufficient to provide a desired therapeutic effect in a subject isdecreased.

The term “subject” includes animals, including mammals and humans,particularly humans.

The term “prodrug” and equivalent expressions refer to agents which canbe converted in vitro or in vivo directly or indirectly to an activeform (see, e.g., R. B. Silverman, 1992, “The Organic Chemistry of DrugDesign and Drug Action,” Academic Press, Chap. 8; Bundgaard, Hans;Editor. Neth. (1985), “Design of Prodrugs”. 360 pp. Elsevier, Amsterdam;Stella, V.; Borchardt, R.; Hageman, M.; Oliyai, R.; Maag, H.; Tilley, J.(Eds.) (2007), “Prodrugs: Challenges and Rewards, XVIII, 1470 p.Springer). Prodrugs can be used to alter the bio-distribution (e.g., toallow agents which would not typically enter the reactive site of aprotease) or the pharmacokinetics for a particular agent. A wide varietyof groups have been used to modify compounds to form prodrugs, forexample, esters, ethers, phosphates, etc. When a prodrug is administeredto a subject, the group is cleaved, enzymatically or non-enzymatically,reductively, oxidatively, or hydrolytically, or otherwise to reveal theactive form. As used herein, “prodrug” includes pharmaceuticallyacceptable salts thereof, or pharmaceutically acceptable solvates aswell as crystalline forms of any of the foregoing. Prodrugs arefrequently, although not necessarily, pharmacologically inactive untilconverted to the active form.

The term “ester” refers to compounds that can be represented by theformula RCOOR (carboxylic ester) or the formula RSO₃R′ (sulfonateester), usually respectively formed by the reaction between a carboxylicor a sulfonic acid and an alcohol usually with the elimination of water.

The term “amino acid” generally refers to an organic compound comprisingboth a carboxylic acid group and an amine group. The term “amino acid”includes both “natural” and “unnatural” or “non-natural” amino acids.Additionally, the term amino acid includes O-alkylated and N-alkylatedamino acids, as well as amino acids having nitrogen or oxygen-containingside chains (such as Lys, Cys, or Ser) in which the nitrogen or oxygenatom has been acylated or alkylated. Amino acids may be pure L or Disomers or mixtures of L and D isomers, including (but not limited to)racemic mixtures.

The term “natural amino acid” and equivalent expressions refer toL-amino acids commonly found in naturally-occurring proteins. Examplesof natural amino acids include, without limitation, alanine (Ala),cysteine (Cys), aspartic acid (Asp), glutamic acid (Glu), phenylalanine(Phe), glycine (Gly), histidine (His), isoleucine (Ile), lysine (Lys),leucine (Leu), methionine (Met), asparagine (Asn), proline (Pro),glutamine (Gln), arginine (Arg), serine (Ser), threonine (Thr), valine(Val), tryptophan (Trp), tyrosine (Tyr), β-alanine (β-Ala), andγ-aminobutyric acid (GABA).

The term “unnatural amino acid” refers to any derivative of a naturalamino acid including D forms, and α- and β-amino acid derivatives. Theterms “unnatural amino acid” and “non-natural amino acid” are usedinterchangeably herein. It is noted that certain amino acids, e.g.,hydroxyproline, that are classified as a non-natural amino acid herein,may be found in nature within a certain organism or a particularprotein. Amino acids with many different protecting groups appropriatefor immediate use in the solid phase synthesis of peptides arecommercially available. In addition to the twenty most common naturallyoccurring amino acids, the following examples of non-natural amino acidsand amino acid derivatives may be used according to the invention(common abbreviations in parentheses): 2-aminoadipic acid (Aad),3-aminoadipic acid (β-Aad), 2-aminobutyric acid (2-Abu),α,β-dehydro-2-aminobutyric acid (8-AU), 1-aminocyclopropane-1-carboxylicacid (ACPC), aminoisobutyric acid (Aib), 3-aminoisobutyric acid (β-Aib),2-amino-thiazoline-4-carboxylic acid, 5-aminovaleric acid (5-Ava),6-aminohexanoic acid (6-Ahx), 2-aminoheptanoic acid (Ahe),8-aminooctanoic acid (8-Aoc), 11-aminoundecanoic acid (11-Aun),12-aminododecanoic acid (12-Ado), 2-aminobenzoic acid (2-Abz),3-aminobenzoic acid (3-Abz), 4-aminobenzoic acid (4-Abz),4-amino-3-hydroxy-6-methylheptanoic acid (Statine, Sta), aminooxyaceticacid (Aoa), 2-aminotetraline-2-carboxylic acid (ATC),4-amino-5-cyclohexyl-3-hydroxypentanoic acid (ACHPA),para-aminophenylalanine (4-NH₂-Phe), 2-aminopimelic acid (Apm),biphenylalanine (Bip), para-bromophenylalanine (4-Br-Phe),ortho-chlorophenylalanine (2-C₁-Phe), meta-chlorophenylalanine(3-C₁-Phe), para-chlorophenylalanine (4-C₁-Phe), meta-chlorotyrosine(3-C₁-Tyr), para-benzoylphenylalanine (Bpa), tert-butylglycine (TLG),cyclohexylalanine (Cha), cyclohexylglycine (Chg), desmosine (Des),2,2-diaminopimelic acid (Dpm), 2,3-diaminopropionic acid (Dpr),2,4-diaminobutyric acid (Dbu), 3,4-dichlorophenylalanine (3,4-C₁₂-Phe),3,4-difluororphenylalanine (3,4-F₂-Phe), 3,5-diiodotyrosine(3,5-I₂-Tyr), N-ethylglycine (EtGly), N-ethylasparagine (EtAsn),ortho-fluorophenylalanine (2-F-Phe), meta-fluorophenylalanine (3-F-Phe),para-fluorophenylalanine (4-F-Phe), meta-fluorotyrosine (3-F-Tyr),homoserine (Hse), homophenylalanine (Hfe), homotyrosine (Htyr),hydroxylysine (Hyl), allo-hydroxylysine (aHyl), 5-hydroxytryptophan(5-OH-Trp), 3- or 4-hydroxyproline (3- or 4-Hyp), para-iodophenylalanine(4-I-Phe), 3-iodotyrosine (3-I-Tyr), indoline-2-carboxylic acid (Idc),isodesmosine (Ide), allo-isoleucine (a-Ile), isonipecotic acid (Inp),N-methylisoleucine (Melle), N-methyllysine (MeLys), meta-methyltyrosine(3-Me-Tyr), N-methylvaline (MeVal), 1-naphthylalanine (1-Nal),2-naphthylalanine (2-Nal), para-nitrophenylalanine (4-NO₂-Phe),3-nitrotyrosine (3-NO₂-Tyr), norleucine (Nle), norvaline (Nva),ornithine (Orn), ortho-phosphotyrosine (H₂PO₃-Tyr),octahydroindole-2-carboxylic acid (Oic), penicillamine (Pen),pentafluorophenylalanine (F₅-Phe), phenylglycine (Phg), pipecolic acid(Pip), propargylglycine (Pra), pyroglutamic acid (PGLU), sarcosine(Sar), tetrahydroisoquinoline-3-carboxylic acid (Tic), thienylalanine,and thiazolidine-4-carboxylic acid (thioproline, Th).

For compounds provided herein, it is intended that, in some embodiments,salts thereof are also encompassed, including pharmaceuticallyacceptable salts. Those skilled in the art will appreciate that manysalt forms (e.g., TFA salt, tetrazolium salt, sodium salt, potassiumsalt, etc.) are possible; appropriate salts are selected based onconsiderations known in the art. The term “pharmaceutically acceptablesalt” refers to salts prepared from pharmaceutically acceptablenon-toxic acids or bases including inorganic acids and bases and organicacids and bases. For example, for compounds that contain a basicnitrogen, salts may be prepared from pharmaceutically acceptablenon-toxic acids including inorganic and organic acids. Suitablepharmaceutically acceptable acid addition salts for the compounds of thepresent invention include without limitation acetic, benzenesulfonic(besylate), benzoic, camphorsulfonic, citric, ethenesulfonic, fumaric,gluconic, glutamic, hydrobromic, hydrochloric, isethionic, lactic,maleic, malic, mandelic, methanesulfonic, mucic, nitric, pamoic,pantothenic, phosphoric, succinic, sulfuric, tartaric acid,p-toluenesulfonic, and the like. When the compounds contain an acidicside chain, suitable pharmaceutically acceptable base addition salts forthe compounds of the present invention include without limitationmetallic salts made from aluminum, calcium, lithium, magnesium,potassium, sodium and zinc or organic salts made from lysine,N,N′-dibenzylethylenediamine, chloroprocaine, choline, diethanolamine,ethylenediamine, meglumine (N-methylglucamine), and procaine.

Compositions

In an embodiment, there is provided a pharmaceutical compositioncomprising a compound of the invention, e.g., a compound of any one ofFormulae (A), and (I) to (IV), or a pharmaceutically acceptable salt,ester, or solvate thereof, and a pharmaceutically acceptable carrier. Inan embodiment, there is provided a pharmaceutical composition comprisinga compound in Tables 1, 2, and 3 or a pharmaceutically acceptable saltthereof, and a pharmaceutically acceptable carrier. In anotherembodiment, there is provided a pharmaceutical composition comprising acompound of any one of Formulae (A), and (I) to (IV) or a compound inTables 1, 2 and 3, or a pharmaceutically acceptable salt thereof, and apharmaceutically acceptable carrier, with the proviso that the compoundis not derived from N-acetyl glucosamine.

The preparation of pharmaceutical compositions can be carried out asknown in the art (see, for example, Remington: The Science and Practiceof Pharmacy, 20^(th) Edition, 2000). For example, a therapeutic compoundand/or composition, together with one or more solid or liquidpharmaceutical carrier substances and/or additives (or auxiliarysubstances) and, if desired, in combination with other pharmaceuticallyactive compounds having therapeutic or prophylactic action, are broughtinto a suitable administration form or dosage form which can then beused as a pharmaceutical in human or veterinary medicine. Pharmaceuticalpreparations can also contain additives, of which many are known in theart, for example fillers, disintegrants, binders, lubricants, wettingagents, stabilizers, emulsifiers, dispersants, preservatives,sweeteners, colorants, flavorings, aromatizers, thickeners, diluents,buffer substances, solvents, solubilizers, agents for achieving a depoteffect, salts for altering the osmotic pressure, coating agents and/orantioxidants.

The term “pharmaceutically acceptable carrier” is intended to encompassany carrier, diluent, adjuvant, excipient, or vehicle, as describedherein. Examples of suspending agents include without limitationethoxylated isostearyl alcohols, polyoxyethylene sorbitol and sorbitanesters, microcrystalline cellulose, aluminum metahydroxide, bentonite,agar-agar and tragacanth, or mixtures of these substances. Prevention ofthe action of microorganisms can be ensured by various antibacterial andantifungal agents, for example, parabens, chlorobutanol, phenol, sorbicacid, and the like. It may also be desirable to include isotonic agents,for example sugars, sodium chloride, and the like. Prolonged absorptionof the injectable pharmaceutical form can be brought about by the use ofagents delaying absorption, for example, aluminum monosterate andgelatin. Examples of suitable carriers, diluents, solvents, or vehiclesinclude without limitation water, ethanol, polyols, suitable mixturesthereof, vegetable oils (such as olive oil), and injectable organicesters such as ethyl oleate. Examples of excipients include withoutlimitation lactose, milk sugar, sodium citrate, calcium carbonate, anddicalcium phosphate. Examples of disintegrating agents include withoutlimitation starch, alginic acids, and certain complex silicates.Examples of lubricants include without limitation magnesium stearate,sodium lauryl sulphate, talc, as well as high molecular weightpolyethylene glycols.

A pharmaceutically acceptable carrier may include any and all solvents,dispersion media, coatings, antibacterial agents, antifungal agents,isotonic agents, absorption delaying agent, and the like that arephysiologically compatible. In one embodiment, the carrier is suitablefor oral administration. Alternatively, the carrier may be suitable forintravenous, intraperitoneal, intramuscular, sublingual or parenteraladministration. In other embodiments, the carrier is suitable fortopical administration, transdermal administration, or foradministration via inhalation. Pharmaceutically acceptable carriers mayinclude sterile aqueous solutions or dispersions and sterile powders forthe extemporaneous preparation of sterile injectable solutions ordispersion. The use of such media and agents for pharmaceutically activesubstances is well known in the art. Except insofar as any conventionalmedia or agent is incompatible with the active compound, use thereof inthe pharmaceutical compositions provided herein is contemplated.

A pharmaceutical composition provided herein can be administered orally,for example in the form of pills, tablets, lacquered tablets,sugar-coated tablets, granules, hard and soft gelatin capsules, aqueous,alcoholic or oily solutions, syrups, emulsions or suspensions, orrectally, for example in the form of suppositories. Administration canalso be carried out parenterally, for example subcutaneously,intramuscularly or intravenously in the form of solutions for injectionor infusion. Other suitable administration forms are, for example,percutaneous or topical administration, for example in the form ofointments, creams, tinctures, sprays or transdermal therapeutic systems,or the inhalative administration in the form of nasal sprays or aerosolmixtures, or, for example, microcapsules, implants or wafers.

In some embodiments, pharmaceutical compositions provided herein aresuitable for oral administration. For example, a pharmaceuticalcomposition may be in the form of a hard shell gelatin capsule, a softshell gelatin capsule, a cachet, a pill, a tablet, a lozenge, a powder,a granule, a pellet, a pastille, or a dragee. Alternatively, apharmaceutical composition may be in the form of a solution, an aqueousliquid suspension, a non-aqueous liquid suspension, an oil-in-waterliquid emulsion, a water-in-oil liquid emulsion, an elixir, a syrup, anointment, or a medical patch. Pharmaceutical compositions may or may notbe enteric coated. In some embodiments, pharmaceutical compositions areformulated for controlled release, such as delayed or extended release.

In further embodiments, compounds and compositions thereof may beformulated in multi-dose forms, i.e., in the form of multi-particulatedosage forms (e.g., hard gelatin capsules or conventional tabletsprepared using a rotary tablet press) comprising one or more bead orminitab populations for oral administration. The conventional tabletsrapidly disperse on entry into the stomach. The one or more coated beador minitab populations may be compressed together with appropriateexcipients into tablets (for example, a binder, a diluent/filler, and adisintegrant for conventional tablets).

Tablets, pills, beads, or minitabs of the compounds and compositions ofthe compounds may be coated or otherwise compounded to provide a dosageform affording the advantage of controlled release, including delayed orextended release, or to protect from the acid conditions of the stomach.For example, the tablet or pill can include an inner dosage and an outerdosage component, the latter being in the form of a coating over theformer. The two components can be separated by a polymer layer thatcontrols the release of the inner dosage.

In certain embodiments, the layer may comprise at least one entericpolymer. In further embodiments, the layer may comprise at least oneenteric polymer in combination with at least one water-insolublepolymer. In still further embodiments, the layer may comprise at leastone enteric polymer in combination with at least one water-solublepolymer. In yet further embodiments, the layer may comprise at least oneenteric polymer in combination with a pore-former.

In certain embodiments, the layer may comprise at least onewater-insoluble polymer. In still further embodiments, the layer maycomprise at least one water-insoluble polymer in combination with atleast one water-soluble polymer. In yet further embodiments, the layermay comprise at least one water-insoluble polymer in combination with apore-former.

Representative examples of water-soluble polymers includepolyvinylpyrrolidone (PVP), hydroxypropyl methylcellulose (HPMC),hydroxypropylcellulose (HPC), polyethylene glycol, and the like.

Representative examples of enteric polymers include esters of celluloseand its derivatives (cellulose acetate phthalate, hydroxypropylmethylcellulose phthalate, hydroxypropyl methylcellulose acetatesuccinate), polyvinyl acetate phthalate, pH-sensitive methacrylicacid-methylmethacrylate copolymers and shellac. These polymers may beused as a dry powder or an aqueous dispersion. Some commerciallyavailable materials that may be used are methacrylic acid copolymerssold under the trademark Eudragit (LI 00, S I 00, L30D) manufactured byRohm Pharma, Cellacefate (cellulose acetate phthalate) from EastmanChemical Co., Aquateric (cellulose acetate phthalate aqueous dispersion)from FMC Corp. and Aqoat (hydroxypropyl methylcellulose acetatesuccinate aqueous dispersion) from Shin Etsu K.K.

Representative examples of useful water-insoluble polymers includeethylcellulose, polyvinyl acetate (for example, Kollicoat SR #30D fromBASF), cellulose acetate, cellulose acetate butyrate, neutral copolymersbased on ethyl acrylate and methylmethacrylate, copolymers of acrylicand methacrylic acid esters with quaternary ammonium groups such asEudragit NE, RS and RS30D, RL or RL30D and the like.

Any of the above polymers may be further plasticized with one or morepharmaceutically acceptable plasticizers. Representative examples ofplasticizers include triacetin, tributyl citrate, triethyl citrate,acetyl tri-n-butyl citrate diethyl phthalate, castor oil, dibutylsebacate, acetylated monoglycerides and the like or mixtures thereof.The plasticizer, when used, may comprise about 3 to 30 wt. % and moretypically about 10 to 25 wt. % based on the polymer. The type ofplasticizer and its content depends on the polymer or polymers andnature of the coating system (e.g., aqueous or solvent based, solutionor dispersion based and the total solids).

Pharmaceutical compositions typically must be sterile and stable underthe conditions of manufacture and storage. A composition can beformulated as a solution, microemulsion, liposome, or other orderedstructure suitable to high drug concentration. The carrier can be asolvent or dispersion medium containing, for example, water, ethanol,polyol (for example, glycerol, propylene glycol, liquid polyethyleneglycol, and the like), and suitable mixtures thereof. The properfluidity can be maintained, for example, by the use of a coating such aslecithin, by the maintenance of the required particle size in the caseof dispersion and by the use of surfactants. In many cases, it will bepreferable to include isotonic agents, for example, sugars, polyalcoholssuch as mannitol, sorbitol, or sodium chloride in the composition.Prolonged absorption of injectable compositions can be brought about byincluding in the composition an agent which delays absorption, forexample, monostearate salts and gelatin. Moreover, a compound can beadministered in a time release formulation, for example in a compositionwhich includes a slow release polymer. The compound can be prepared withcarriers that will protect against rapid release, such as a controlledrelease formulation, including implants and microencapsulated deliverysystems. Biodegradable, biocompatible polymers can be used, such asethylene vinyl acetate, polyanhydrides, polyglycolic acid, collagen,polyorthoesters, polylactic acid and polylactic, polyglycolic copolymers(PLG).

Many methods for the preparation of such formulations are generallyknown to those skilled in the art. Sterile injectable solutions can beprepared by incorporating a compound, such as a compound of Formulae(A), and (I)-(IV) provided herein, in the required amount in anappropriate solvent with one or a combination of ingredients enumeratedabove, as required, followed by filtered sterilization. Generally,dispersions are prepared by incorporating the active compound into asterile vehicle that contains a basic dispersion medium and the requiredother ingredients from those enumerated above. In the case of sterilepowders for the preparation of sterile injectable solutions, commonmethods of preparation are vacuum drying and freeze-drying which yieldsa powder of the active ingredient plus any additional desired ingredientfrom a previously sterile-filtered solution thereof. Compounds may alsobe formulated with one or more additional compounds that enhance theirsolubility.

It is often advantageous to formulate compositions (such as parenteralcompositions) in dosage unit form for ease of administration anduniformity of dosage. The term “unit dosage form” refers to a physicallydiscrete unit suitable as unitary dosages for human subjects and otheranimals, each unit containing a predetermined quantity of activematerial calculated to produce the desired therapeutic effect, inassociation with a suitable pharmaceutical carrier. The specificationfor the dosage unit forms of the invention may vary and are dictated byand directly dependent on (a) the unique characteristics of thetherapeutic compound and the particular therapeutic effect to beachieved, and (b) the limitations inherent in the art of compoundingsuch a therapeutic compound. Dosages are discussed further below.

In some embodiments, there are provided pharmaceutical compositions thatcomprise an effective amount of a compound and/or composition describedherein, and a pharmaceutically acceptable carrier. In an embodiment,there are provided pharmaceutical compositions for the treatment orprevention of a bone or joint disorder comprising a compound describedherein, or a pharmaceutically acceptable salt thereof, and apharmaceutically acceptable carrier. In an embodiment, there areprovided pharmaceutical compositions for the treatment or prevention ofosteoporosis comprising a compound described herein, or apharmaceutically acceptable salt thereof, and a pharmaceuticallyacceptable carrier. In an embodiment, there are provided pharmaceuticalcompositions for the treatment or prevention of arthritis comprising acompound described herein, or a pharmaceutically acceptable saltthereof, and a pharmaceutically acceptable carrier.

In some embodiments, there are provided pharmaceutical compositions thatcomprise an effective amount of a GlcNBu prodrug and a pharmaceuticallyacceptable carrier. Such compositions may be used for the treatment orprevention of a bone or joint disorder such as osteoporosis andarthritis and for other methods as described herein. In some suchembodiments, the GlcNBu prodrug may be a compound of Formulae (A), and(I) to (IV) or a pharmaceutically acceptable salt thereof. In someembodiments, treatment or prevention are within the context of thepresent invention if there is a measurable difference between theperformances of subjects treated using the compounds and methodsprovided herein as compared to members of a placebo group, historicalcontrol, or between subsequent tests given to the same subject.

It should be understood that the dosage or amount of a compound and/orcomposition used, alone or in combination with one or more activecompounds to be administered, depends on the individual case and is, asis customary, to be adapted to the individual circumstances to achievean optimum effect. Dosing and administration regimens are within thepurview of the skilled artisan, and appropriate doses depend upon anumber of factors within the knowledge of the ordinarily skilledphysician, veterinarian, or researcher (e.g., see Wells et al. eds.,Pharmacotherapy Handbook, 2nd Edition, Appleton and Lange, Stamford,Conn. (2000); PDR Pharmacopoeia, Tarascon Pocket Pharmacopoeia 2000,Deluxe Edition, Tarascon Publishing, Loma Linda, Calif. (2000)). Forexample, dosing and administration regimens may depend on the nature andthe severity of the disorder to be treated, and also on the sex, age,weight and individual responsiveness of the human or animal to betreated, on the efficacy and duration of action of the compounds used,on whether the therapy is acute or chronic or prophylactic, and/or onwhether other active compounds are administered in addition to thetherapeutic molecule(s).

Thus the dose(s) of a compound or composition will vary depending upon avariety of factors including, but not limited to: the activity,biological and pharmacokinetic properties and/or side effects of thecompound being used; the age, body weight, general health, gender, anddiet of the subject; the time of administration, the route ofadministration, the rate of excretion, and any drug combination, ifapplicable; the effect which the practitioner desires the compound tohave upon the subject; and the properties of the compound beingadministered (e.g., bioavailability, stability, potency, toxicity,etc.). Such appropriate doses may be determined as known in the art.When one or more of the compounds or compositions described herein is tobe administered to a human, a physician may for example, prescribe arelatively low dose at first, subsequently increasing the dose until anappropriate response is obtained.

There are no particular limitations on the dose of each of the compoundsfor use in compositions provided herein. Exemplary doses includemilligram or microgram amounts of the compound per kilogram of subjector sample weight (e.g., about 50 micrograms per kilogram to about 3000milligrams per kilogram, about 1 milligram per kilogram to about 100milligrams per kilogram, about 1 milligram per kilogram to about 50milligram per kilogram, about 1 milligram per kilogram to about 10milligrams per kilogram, or about 3 milligrams per kilogram to about 5milligrams per kilogram). Additional exemplary doses include doses ofabout 5 to about 500 mg, about 25 to about 300 mg, about 25 to about 200mg, about 50 to about 150 mg, or about 50, about 100, about 150 mg,about 200 mg, about 250 mg, about 500 mg, about 1000 mg, about 2000 mgand, about 3000 mg for example, daily or twice daily, or lower or higheramounts.

In some embodiments, the dose range for adult humans is generally from0.005 mg to 10 g/day orally. Tablets or other forms of presentationprovided in discrete units may conveniently contain an amount of acompound (e.g., of Formula I, Formula II, or Formula III) which iseffective at such dosage or as a multiple of the same, for instance,units containing 5 mg to 500 mg, usually around 10 mg to 200 mg. Adosage unit (e.g., an oral dosage unit) can include from, for example, 1to 30 mg, 1 to 40 mg, 1 to 100 mg, 1 to 300 mg, 1 to 500 mg, 2 to 500mg, 3 to 100 mg, 5 to 20 mg, 5 to 100 mg (e.g. 1 mg, 2 mg, 3 mg, 4 mg, 5mg, 6 mg, 7 mg, 8 mg, 9 mg, 10 mg, 11 mg, 12 mg, 13 mg, 14 mg, 15 mg, 16mg, 17 mg, 18 mg, 19 mg, 20 mg, 25 mg, 30 mg, 35 mg, 40 mg, 45 mg, 50mg, 55 mg, 60 mg, 65 mg, 70 mg, 75 mg, 80 mg, 85 mg, 90 mg, 95 mg, 100mg, 150 mg, 200 mg, 250 mg, 300 mg, 350 mg, 400 mg, 450 mg, 500 mg, 1000mg, 2000 mg, or 3000 mg) of a compound described herein.

In some embodiments, the dosage range for oral administration isgenerally about 0.001 mg to about 3000 mg of a compound per kg bodymass. In some embodiments, the oral dose is 0.01 mg to 100 mg per kgbody mass, 0.1 mg to 50 mg per kg body mass, 0.5 mg to 20 mg per kg bodymass, or 1 mg to 10 mg per kg body mass. In some embodiments, the oraldose is 5 mg of a compound per kg body mass.

Administration of compounds and compositions provided herein can becarried out using known procedures, at dosages and for periods of timeeffective to achieve a desired purpose. Dosage regimens can be adjustedto provide the optimum therapeutic response. For example, severaldivided doses may be administered daily or the dose may beproportionally reduced as indicated by the exigencies of the therapeuticsituation. In some embodiments, a compound or composition isadministered at an effective dosage sufficient to prevent or treat abone or joint disease, e.g., osteoporosis and/or arthritis, in asubject. Further, a compound or composition may be administered usingany suitable route or means, such as without limitation via oral,parenteral, intravenous, intraperitoneal, intramuscular, sublingual,topical, transdermal, or nasal administration, via inhalation, or viasuch other routes as are known in the art.

The compounds and compositions provided herein may be administered once,twice, three, or four times daily, using any suitable mode describedabove. Also, in certain embodiments, administration or treatment withthe compounds according to any of the formulae described herein may becontinued for a number of weeks; for example, commonly treatment wouldcontinue for at least 2 weeks, 4 weeks, 8 weeks, 12 weeks, 16 weeks, 20weeks, 24 weeks, 28 weeks, 32 weeks, 36 weeks, 40 weeks, 44 weeks, 48weeks, 52 weeks, 56 weeks, 60 weeks, 64 weeks, 68 weeks, 72 weeks, 76weeks, 80 weeks, 84 weeks, 88 weeks, 92 weeks, 96 weeks, 100 weeks, or104 weeks. In yet further embodiments, administration or treatment withthe compounds according to any of the formulae described herein may becontinued for a number of months; for example, commonly treatment wouldcontinue for at least 2 months, 4 months, 6 months, 8 months, 10 months,12 months, 15 months, 18 months, 20 months, or 24 months. In stillfurther embodiments, administration or treatment with the compoundsaccording to any of the formulae described herein may be continuedindefinitely.

Therapeutic Methods

In some embodiments, there are provided methods of treating orpreventing a bone or joint disorder in a subject in need thereofcomprising administering an effective amount of a compound, GlcNBuprodrug, or pharmaceutical composition thereof as described herein tothe subject, such that the bone or joint disorder is prevented ortreated in the subject.

A wide range of bone or joint disorders may be treated or prevented bythe methods provided herein, including without limitation osteoporosis,osteopenia, and/or arthritis. Many types of arthritis are known and maybe treated or prevented using methods provided herein, including withoutlimitation osteoarthritis, inflammatory arthritis (e.g., rheumatoidarthritis, psoriatic arthritis, etc.), traumatic arthritis, degenerativearthritis, and dysplastic arthritis.

In an embodiment, there is provided a method of enhancing cartilageformation in a subject.

In an embodiment, there is provided a method of enhancing chondrocytecell proliferation or growth in a subject.

In an embodiment, there is provided a method of alleviating the symptomsof joint stiffness and/or restricted mobility in a subject.

In an embodiment, there is provided a method of enhancing the productionof glycosaminoglycan in a subject.

In an embodiment, there is provided a method of increasing bone mineraldensity (BMD) in a subject.

In an embodiment, there is provided a method of improving bonemicro-architecture and/or bone connectivity in a subject.

In an embodiment, there is provided a method of treating or preventinglow BMD in a subject.

In an embodiment, there is provided a method of preventing ordiminishing the risk of fractures in a subject.

In an embodiment, there is provided a method of treating or preventingbone fractures, e.g., low impact fractures and/or high impact factures,in a subject.

In some embodiments, there are provided methods of increasing thetherapeutic effectiveness of GlcNBu in a subject in need thereof,comprising administering an effective amount of a compound, GlcNBuprodrug, or pharmaceutical composition thereof as described herein tothe subject, such that the therapeutic effectiveness of GlcNBu isincreased as compared to administration of GlcNBu.

In some embodiments, one or more of the following is increased byadministration of the compound, GlcNBu prodrug, or pharmaceuticalcomposition provided herein: bioavailability of GlcNBu; AUC of GlcNBu inblood or plasma; C_(max) of GlcNBu; T_(max) of GlcNBu; t_(1/2) ofGlcNBu; therapeutic bio-distribution of GlcNBu; therapeutic level ofGlcNBu in a selected tissue; and/or bioabsorption of GlcNBu in asubject, as compared to administration of GlcNBu itself. In someembodiments, one or more of the following is reduced by administrationof the compound, GlcNBu prodrug, or pharmaceutical composition providedherein: metabolism of GlcNBu; and side effects of GlcNBu in a subject,as compared to administration of GlcNBu itself.

In some embodiments, there are provided methods of attaining a targetpharmacokinetic parameter for GlcNBu in a subject, comprisingadministering an effective amount of a compound, GlcNBu prodrug, orpharmaceutical composition thereof as described herein to the subject,such that the target pharmacokinetic parameter for GlcNBu is attained inthe subject. Non-limiting examples of target pharmacokinetic parametersinclude a target bioavailability, AUC in blood or plasma, C_(max),T_(max), bio-distribution, level in a selected tissue, half-life(t_(1/2)), bioabsorption, and amount or rate of metabolism.Pharmacokinetic parameters may be calculated using methods known in theart.

In some embodiments of methods provided herein, the subject is a mammal,e.g., a human.

In some embodiments of methods provided herein, there are providedmethods of treating or preventing a bone or joint disorder in a subjectin need thereof comprising administering an effective amount of acompound, GlcNBu prodrug, or pharmaceutical composition thereof asdescribed herein in combination with one or more other therapeutic agentto the subject, such that the bone or joint disorder is prevented ortreated in the subject. It should be understood that compounds and/orcompositions provided herein may be used alone or in combination withother suitable therapies for bone or joint disorders, includingtherapies for osteoporosis, arthritis, etc. Non-limiting examples ofsuch other therapies for bone or joint disorders includebisphosphonates, denosumab, calcitonic, selective estrogen receptormodulators (SERMs) such as raloxifene, teriparatide, duloxetine, andnonsteroidal anti-inflammatory drugs (NSAIDs). Compounds and/orcompositions described herein may be administered alone or incombination with the one or more additional therapy for bone or jointdisorders. The latter can be administered before, after orsimultaneously with the administration of the compounds and/orcompositions described herein.

EXAMPLES

The present invention will be more readily understood by referring tothe following examples, which are provided to illustrate the inventionand are not to be construed as limiting the scope thereof in any manner.

Unless defined otherwise or the context clearly dictates otherwise, alltechnical and scientific terms used herein have the same meaning ascommonly understood by one of ordinary skill in the art to which thisinvention belongs. It should be understood that any methods andmaterials similar or equivalent to those described herein can be used inthe practice or testing of the invention.

Example 1. Preparation of2-N-butyryl-6-O—(N,O-bis(t-butoxycarbonyl)-L-tyrosyl)-D-glucosamine(Compound 1)

To a mixture of L-tyrosine (3.62 g, 20 mmol, 1 eq.) in water (50 mL)under stirring was added a solution of Boc₂O (13.08 g, 60 mmol, 3 eq.)in isopropanol (IPA, 25 mL, followed by dropwise addition of 8 M KOHaqueous solution until the pH of the reaction mixture reached 12. Themixture was stirred at r.t for 3 h, acidified to pH 3 with 1 M HClaqueous solution, and then extracted with ethyl acetate (100 mL). Theorganic layer was washed with water (50 mL) and brine (50 mL)subsequently, and then evaporated to dryness on a rotary evaporator,giving N,O-bis(t-butoxycarbonyl)-L-tyrosine (7.68 g, 100%). Thiscompound (7.68 g, 20 mmol, 1 eq.) was added to DMF (50 mL), followed byaddition of N-butyryl-D-glucosamine (GlcNBu, 4.98 g, 20 mmol, 1 eq.),N-hydroxybenzotrizole (HOBt, 4.05 g, 30 mmol, 1.5 eq.),N-(3-dimethylaminopropyl)-N-ethylcarbodiimide (EDCI, 7.64 g, 40 mmol, 2eq.), and N,N-diisopropylethylamine (DIPEA, 7.74 g, 60 mmol, 3 eq.). Themixture was stirred at r.t. for 16 h, followed by addition of water (50mL) and ethyl acetate (50 mL). The organic layer was separated, washedwith water (50 mL) and then with brine (50 mL), and evaporated todryness. The residue was purified on a silica-gel column(MeOH/DCM=1/50˜1/40), providing the title compound (2.21 g, 17.9%): ¹HNMR (CD₃OD, 500 MHz) δ ppm 0.95 (t, 3H), 1.39 (s, 9H), 1.52 (s, 9H),1.64 (dt, 2H), 2.22 (t, 2H), 2.92-2.96 (m, 0.8H), 3.16-3.20 (m, 1H),3.34-3.52 (m, 1.2H), 3.71 (t, 0.8H), 3.87 (dd, 0.8H), 4.01-4.04 (m,0.8H), 4.27-4.30 (m, 1H), 4.40-4.49 (m, 1.8H), 4.60 (d, 0.2H), 5.10 (d,0.8H), 7.04 (d, 2H), 7.26 (d, 2H); ¹³C NMR (CD₃OD, 125 MHz) δ ppm 12.55,18.96, 26.47, 27.27, 36.54, 37.49, 54.29, 55.00, 64.38, 69.23, 71.06,79.30, 82.84, 91.22, 120.82, 129.99, 134.70, 150.03, 152.12, 156.40,171.98, 175.14.

Example 2. Preparation of2-N-butyryl-6-O—(N-(t-butoxycarbonyl)-L-valyl)-D-glucosamine (Compound2)

To a mixture of N-Boc-L-valine (2.17 g, 10 mmol, 1 eq.) in DMF (50 mL)were added GlcNBu (2.49 g, 10 mmol, 1 eq.), HOBt (1.62 g, 12 mmol, 1.2eq.), EDCI (2.88 g, 15 mmol, 1.5 eq.), and DIPEA (3.88 g, 30 mmol, 3eq.). The mixture was stirred at r.t. for 16 h, followed by addition ofwater (50 mL) and ethyl acetate (50 mL), and mixed well. The organiclayer was separated, washed with water (50 mL) and brine (50 mL)subsequently, and evaporated to dryness. The residual material waspurified on a silica-gel column (MeOH/DCM, 1/35 to 1/30, v/v), givingthe title compound (1.43 g, 32.0%): ¹H NMR (CD₃OD, 500 MHz) δ ppm0.92-0.96 (m, 9H), 1.44 (s, 9H), 1.65 (dt, 2H), 2.12 (tt, 1H), 2.20-2.22(m, 2H), 3.42-3.50 (m, 1.3H), 3.60 (t, 0.7H), 3.70 (t, 0.3H), 3.84 (dd,0.3H), 3.93-4.06 (m, 1.3H), 4.22-4.27 (m, 1H), 4.42-4.49 (m, 1H), 4.58(d, 0.7H), 5.00 (d, 0.3H); ¹³C NMR (CD₃OD, 125 MHz) δ ppm 13.94, 18.31,19.59, 28.72, 31.96, 38.90, 39.29, 55.69, 58.64, 60.62, 65.39, 70.68,72.68, 80.61, 92.59, 97.11, 158.25, 173.65, 176.52, 177.11.

Example 3. Preparation of2-N-butyryl-6-O—(N—(N-Boc-L-glycyl)-L-valyl)-D-glucosamine (Compound 3)

To a mixture of 2-N-butyryl-6-O-(L-valyl)-D-glucosamine hydrochloride(see Example 5 for its preparation, 3.84 g, 10 mmol, 1 eq.) indichloromethane (DCM, 50 mL) was added triethylamine (2.0 g, 20 mmol, 2eq.). The mixture was stirred at r.t. for 10 min., followed by additionof N-Boc-glycine N-hydroxysuccinimide ester (2.72 g, 10 mmol, 1 eq.).The mixture was stirred for 1 h, quenched with brine. The organic layerwas separated, washed with brine (50 mL), and evaporated to dryness. Theresidual material was purified on a silica-gel column (MeOH/DCM, 1/100to 1/30), providing the title compound (3.81 g, 75.6%): ¹H NMR (CD₃OD,500 MHz) δ ppm 0.90-0.97 (m, 9H), 1.45 (s, 9H), 1.66 (dt, 2H), 2.14-2.24(m, 3H), 3.38-3.46 (m, 0.7H), 3.68-4.03 (m, 4.5H), 4.24-4.58 (m, 3H),5.07 (s, 0.7H), 5.48 (s, 0.3H); ¹³C NMR (CD₃OD, 125 MHz) δ ppm 13.96,18.29, 20.36, 28.69, 38.91, 44.42, 55.73, 59.02, 59.17, 65.12, 70.66,72.43, 80.75, 92.62, 158.48, 172.63, 172.89, 176.54.

Example 4. Preparation of2-N-butyryl-6-O—(N-(L-glycyl)-L-valyl)-D-glucosaminehydrochloride(Compound 4)

To compound 3 (5.05 g, 10 mmol, 1 eq.) in DCM (50 mL) was added 4M HClin dioxane (5 mL). The mixture was stirred at room temperature (r.t.)for 1 hour (h). Solvent was removed on a rotary evaporator, giving thetitle compound (4.41 g, 100.0%): ¹H NMR (D₂O, 500 MHz) δ ppm 0.86-0.91(m, 9H), 1.57 (dt, 2H), 2.12-2.17 (m, 3H), 3.22-3.42 (m, 3H), 3.50-3.57(m, 2H), 3.64 (t, 0.6H), 3.74-3.77 (m, 0.6H), 3.82-3.93 (m, 0.6H),3.14-3.53 (m, 3.3H), 4.98 (t, 0.6H).

Example 5. Preparation of 2-N-butyryl-6-O-(L-valyl)-D-glucosaminehydrochloride (Compound 5)

To a stirred mixture of compound 2 (0.9 g, 2 mmol, 1 eq.) in DCM (9 mL)was added 4M HCl in dioxane (92.7. mL). The mixture was stirred at r.t.for 1 h, and evaporated to dryness, affording the title compound (0.77g, 100%): ¹H NMR (CD₃OD, 500 MHz) δ ppm 0.78-0.82 (m, 3H), 0.96 (d, 6H),1.5 (dt, 2H), 2.14-2.19 (m, 2H), 2.25-2.32 (m, 1H), 3.38-3.47 (m,1.35H), 3.56-3.69 (m, 1.35H), 3.77-3.80 (m, 0.65H), 3.99-4.00 (m,1.75H), 4.39-4.49 (m, 2H), 4.63 (d, 0.4H), 5.07 (d, 0.6H); ¹³C NMR(CD₃OD, 125 MHz) δ ppm 12.51, 17.01, 17.15, 18.92, 29.28, 37.44, 37.87,53.78, 56.30, 58.28, 64.66, 69.08, 69.76, 70.08, 70.32, 90.85, 94.93,169.48, 177.54, 177.76; m/z (ESI⁺) 349.0.

Example 6. Preparation of 1,3,4,6-tetra-O-2-N-pentabutyryl-D-glucosamine(Compound 6)

To a mixture of GlcNBu (2.17 g, 5 mmol, 1 eq.) in pyridine (15 mL) wereadded 4-dimethylamonopyridine (DMAP, 0.06 g, 0.5 mmol, 0.1 eq.) andbutyric anhydride (3.96 g, 25 mmol, 5 eq.). The mixture was stirred atr.t. for 16 h. Solvent was removed on a rotary evaporator, and theresidual material was purified on a silica-gel column (EA/PE, 1/10 to1/3), giving the title compound (2.5 g, 94.3%): ¹H NMR (CDCl₃, 500 MHz)δ ppm 0.86-0.99 (m, 15H), 1.52-1.73 (m, 10H), 2.03-2.081 (m, 2H),2.20-2.40 (m, 8H), 3.76-3.79 (m, 0.4H), 3.96-3.97 (m, 0.6H), 4.06-4.23(m, 2H), 4.30-4.36 (m, 0.4H), 4.44-4.48 (m, 0.6H), 5.10-5.27 (m, 2H),5.49 (d, 1H), 5.66 (d, 0.4H), 6.20 (d, 0.6H); ¹³C NMR (CDCl₃, 125 MHz) δppm 13.64, 18.09, 18.39, 18.95, 35.89, 35.93, 35.99, 36.06, 36.09,38.43, 51.24, 52.81, 61.47, 67.19, 67.43, 70.01, 70.40, 73.17, 90.46,92.69, 171.31, 171.75, 171.84, 172.26, 172.75, 173.34, 173.91, 174.54;m/z (ESI⁻) 528.2.

Example 7. Preparation of 2-N-butyryl-6-O-linolyl-D-glucosamine(Compound 7)

To linoleic acid (2.8 g, 10 mmol, 1 eq.) in DMF (60 mL) were addedGlcNBu (2.49 g, 10 mmol, 1 eq.), HOBt (1.62 g, 12 mmol, 1.2 eq), EDCI(2.88 g, 15 mmol, 1.5 eq.), DIPEA (3.88 g, 30 mmol, 3 eq.). The mixturewas stirred at r.t. for 16 h, followed by addition of water (50 mL) andethyl acetate (50 mL) and well mixed. The organic layer was separated,washed with water (50 mL) and brine (50 mL) subsequently, and evaporatedto dryness. The residual material was purified on a silica-gel column(MeOH/DCM, 1/70 to 1/50), finishing the title compound (0.60 g, 11.7%):¹H NMR (CD₃OD, 500 MHz) δ ppm 0.89-0.97 (m, 6H), 1.29-1.38 (m, 16H),1.61-1.68 (m, 4H), 2.04-2.07 (m, 4H), 2.22 (t, 2H), 2.34 (t, 2H), 2.77(t, 2H), 3.35 (t, 0.8H), 3.42-3.62 (m, 0.5H), 3.70 (t, 0.8H), 3.84-3.86(m, 0.9H), 3.93-3.99 (m, 1H), 4.19-4.22 (m, 0.9H), 4.36-4.38 (m, 0.9H),4.58 (d, 0.1H), 5.07 (d, 0.9H), 5.29-5.39 (m, 4H); ¹³C NMR (CD₃OD, 125MHz) δ ppm 12.56, 13.03, 18.96, 24.60, 26.75, 28.81, 29.07, 37.49,47.07, 47.59, 54.29, 63.37, 69.33, 71.06, 71.18, 91.22, 127.64, 127.67,129.47, 129.52, 174.07, 175.11; m/z (ESI⁺) 512.2.

Example 8. Preparation of2-N-butyryl-1,3,4,6-tetra-O-tetraacetyl-D-glucosamine (Compound 8)

To a mixture of GlcNBu (2.17 g, 5 mmol, 1 eq.) in pyridine (15 mL) wereadded DMAP (0.06 g, 0.5 mmol, 0.1 eq.), acetic anhydride (2.55 g, 25mmol, 5 eq.). The mixture was stirred at r.t. for 16 h. Solvent wasremoved on a rotary evaporator; and the residual material was purifiedon a silica-gel column (EA/PE, 1/10 to 1/3), giving the title compound(2.0 g, 95.9%): ¹H NMR (CDCl₃, 500 MHz) δ ppm 0.87-0.90 (t, 3H),1.52-1.63 (m, 2H), 2.02-2.04 (m, 6H), 2.07-2.12 (m, 6H), 2.15-2.21 (m,2H), 3.79 (s, 0.35H), 3.98-4.13 (m, 1.65H), 4.23-4.35 (m, 1.35H),4.46-4.51 (m, 0.65H), 5.09-5.26 (m, 2H), 5.50-5.54 (m, 1H), 5.67 (d,0.35H), 6.18 (d, 0.65H); ¹³C NMR (CDCl₃, 125 MHz) δ ppm 13.66, 19.08,19.14, 20.72, 20.87, 38.54, 38.73, 51.06, 52.92, 61.68, 61.76, 67.60,67.76, 69.86, 70.75, 73.13, 90.82, 92.84, 168.73, 169.24, 169.37,169.68, 170.86, 171.29, 171.90, 172.96, 173.08; m/z (ESI⁺) 416.2.

Example 9. Preparation of 2-N-butyryl-6-O-lipoyl-D-glucosamine (Compound9)

To a mixture of lipoic acid (2.06 g, 10 mmol, 1 eq.) in DMF (60 mL) wereadded GlcNBu (2.49 g, 10 mmol, 1 eq.), HOBt (1.62 g, 12 mmol, 1.2 eq.),EDCI (2.88 g, 15 mmol, 1.5 eq.), and DIPEA (3.88 g, 30 mmol, 3 eq.). Themixture was stirred at r.t. for 16 h, followed by addition of water (50mL) and ethyl acetate (50 mL). The organic layer was separated, washedwith water (50 mL) and brine (50 mL), and evaporated to dryness. Theresidual material was purified on a silica-gel column (MeOH/DCM, 1/70 to1/40), providing the title compound (0.20 g, 4.6%): ¹H NMR (DMSO, 500MHz) δ ppm 0.84 (t, 3H), 1.23-1.69 (m, 8.8H), 1.82-2.09 (m, 3.2H),2.31-2.44 (m, 2.5H), 2.80 (s, 1H), 3.08-3.21 (m, 2H), 3.45-3.54 (m,0.8H), 3.58-3.66 (m, 1.6H), 3.79 (d, 0.8H), 4.02 (d, 0.8H), 4.30 (d,0.8H), 4.69 (d, 0.7H), 4.90 (s, 0.9H), 5.17 (d, 0.8H), 6.53 (d, 0.8H),7.54 (d, 0.8H); ¹³C NMR (DMSO, 125 MHz) δ ppm 14.12, 19.14, 24.70,28.55, 33.74, 34.51, 37.56, 38.54, 54.48, 55.38, 56.49, 69.68, 70.65,71.57, 91.16, 172.65, 173.28; m/z (ESI⁺) 438.0.

Example 10. Preparation of2-N-butyryl-1,6-di-O-di(L-phenylalanyl)-D-glucosamine hydrochloride(Compound 10)

To a mixture of L-phenylalanine (3.30 g, 20 mmol, 1 eq.) in MeOH (50 mL)were added Boc₂O (6.54 g, 30 mmol, 1.5 eq.) and triethylamine (3.5 g, 35mmol, 1.75 eq.). The mixture was stirred at 50° C. for 1 h. Solvent wasremoved on a rotary evaporator; and the residual material was taken intoDMF (100 mL), followed by addition of GlcNBu (4.98 g, 20 mmol, 1 eq.),HOBt (4.05 g, 30 mmol, 1.5 eq.), EDCI (7.64 g, 40 mmol, 2 eq.), andDIPEA (7.74 g, 60 mmol, 3 eq.). The mixture was stirred at r.t. for 16h, followed by addition of water (50 mL) and ethyl acetate (50 mL). Theorganic layer was separated, washed with water (50 mL) and brine (50mL), subsequently. Solvent was removed (rotary evaporation); and theresidual material was purified (silica-gel column; eluent, MeOH/DCM,1/80 to 1/65), giving the corresponding intermediate (1.1 g, 7.40%).This intermediate (1.1 g, 1.48 mmol, 1 eq.) was dissolved in DCM (11mL), followed by addition (while a stirring was applied) of 4M HCl indioxane (1.1 mL). The mixture was stirred at r.t. for 1 h, and then thesolvent was removed by rotary evaporator, affording the title compound(0.74 g, 83.0%): ¹H NMR (D₂O, 500 MHz) δ ppm 0.70-0.83 (m, 3H),1.20-1.26 (m, 0.5H), 1.55 (d, 1.8H), 2.19-2.52 (m, 2H), 3.12-3.38 (m,5H), 3.44 (d, 0.8H), 3.58-3.70 (m, 1H), 3.78-3.99 (m, 1.5H), 4.21 (t,0.8H), 4.41-4.47 (m, 3.2H), 5.00-5.35 (m, 0.4H), 6.23-6.42 (m, 0.4H),7.20-7.37 (m, 10H); ¹³C NMR (D₂O, 125 MHz) δ ppm 12.58, 12.69, 17.65,18.94, 35.27, 35.51, 35.67, 37.49, 52.45, 53.73, 53.91, 54.41, 64.85,69.02, 69.62, 69.85, 70.31, 88.93, 89.16, 90.90, 92.90, 94.98, 127.92,128.10, 129.16, 129.25, 129.34, 133.63, 134.10, 169.23, 171.84, 174.35,177.56; m/z (ESI⁺) 544.1.

Example 11. Preparation of2-N-Butyryl-6-O-(L-phenylalanyl)-D-glucosamine hydrochloride (Compound11)

To a mixture of L-phenylalanine (3.30 g, 20 mmol, 1 eq.) in MeOH (50 mL)was added (while stirring applied) Boc₂O (6.54 g, 30 mmol, 1.5 eq.) andtriethylamine (3.5 g, 35 mmol, 1.75 eq.). The mixture was stirred atr.t. for 1 h. Solvent was removed by rotary evaporation; and theresidual material was taken into DMF (100 mL), followed by addition ofGlcNBu (4.98 g, 20 mmol, 1 eq.), HOBt (4.05 g, 30 mmol, 1.5 eq.), EDCI(7.64 g, 40 mmol, 2 eq.), and DIPEA (7.74 g, 60 mmol, 3 eq.). Themixture was stirred at r.t. for 16 h, followed by addition, to themixture, of water (50 mL) and ethyl acetate (50 mL). The organic layerwas separated, washed with water (50 mL) and brine (50 mL),subsequently. After the solvent was evaporated, the residual materialwas purified on a silica-gel column (MeOH/DCM, 1/65 to 1/40), giving6-O—(N-Boc-L-phenylalanyl)-2-N-butyryl-D-glucosamine (1.7 g, 17.1%) asan intermediate. This intermediate (1.7 g, 3.42 mmol, 1 eq.) wasdissolved in DCM (17 mL). To the stirred solution was added 4 M HClsolution in dioxane (1.7 mL). The mixture was stirred at r.t. for 1 h,and evaporated to dryness, providing the title compound (1.30 g, 88.1%):¹H NMR (D₂O, 500 MHz) δ ppm 0.71-0.83 (m, 3H), 1.17-1.29 (m, 0.7H),1.53-1.58 (m, 2H), 2.20-2.23 (m, 2H), 2.69 (d, 0.2H), 3.20-3.34 (m, 3H),3.47 (t, 0.4H), 3.59-3.70 (m, 1.2H), 3.78 (d, 0.6H), 4.00 (d, 0.6H),4.38-4.50 (m, 2.8H), 4.67 (d, 0.4H), 5.09 (d, 0.6H), 7.26-7.38 (m, 5H);¹³C NMR (D₂O, 125 MHz) δ ppm 12.58, 18.94, 35.55, 37.49, 37.91, 53.73,53.91, 56.29, 64.84, 68.99, 69.61, 69.84, 70.31, 90.90, 94.98, 128.10,129.23, 129.32, 133.67, 169.33, 177.56, 177.80; m/z (ESI⁺) 397.0.

Example 12. Preparation of1,3,4-tri-O-2-N-tetrabutyryl-6-O-(L-valyl)-D-glucosamine hydrochloride(Compound 12)

To a mixture of compound 2 (1.50 g, 3.3 mmol, 1 eq.) in pyridine (15 mL)were added, while stirring applied, butyric anhydride (1.85 g, 11.7mmol, 3.5 eq.) and DMAP (0.04 g, 0.3 mmol, 0.1 eq.). The mixture wasstirred at 40° C. for 1 h and at r.t. overnight. Solvent was evaporated;and the residual material was purified on a silica-gel column (A/PE, 1/5to 1/2), providing an N-Boc intermediate (0.7 g, 34.9%). Thisintermediate (0.7 g, 1.2 mmol, 1 eq.) was taken into DCM (7 mL),followed by addition of 4 MHCl in dooxane (0.7 mL) with stirring. Themixture was stirred at r.t. for 1 h and then evaporated to dryness,finishing with the title compound (0.7 g, quantitative): ¹H NMR (MeOH,500 MHz) δ ppm 0.87-1.09 (m, 18H), 1.58-1.71 (m, 8H), 2.13-2.51 (m, 9H), 3.99-4.43 (m, 4.8H), 5.07-5.37 (m, 2.3H), 6.10-6.25 (m, 0.9H),7.88-8.10 (m, 0.7H); ¹³C NMR (MeOH, 125 MHz) δ ppm 12.50, 12.56, 16.84,17.69, 17.89, 29.51, 35.02, 35.28, 35.45, 50.40, 58.05, 63.21, 68.19,69.26, 69.91, 89.75, 168.45, 171.84, 172.30, 172.78, 175.15; m/z (ESI⁺)558.9.

Example 13. Preparation of 2-N-butyryl-6-O-(L-histidyl)-D-glucosaminehydrochloride (Compound 13)

To a mixture of L-histidine (3.10 g, 20 mmol, 1 eq.) in MeOH (50 mL)were added Boc₂O (13.1 g, 60 mmol, 3.0 eq.) and triethylamine (7.0 g, 70mmol, 3.5 eq.). The mixture was stirred at 50° C. until a clear solutionwas obtained (around 2 h). Solvent was removed on a rotary evaporator;and the residual material was taken into DMF (100 mL), followed byaddition of GlcNBu (4.98 g, 20 mmol, 1 eq.), HOBt (4.05 g, 30 mmol, 1.5eq.), EDCI (7.64 g, 40 mmol, 2 eq.), DIPEA (7.74 g, 60 mmol, 3 eq.). Themixture was stirred at r.t. for 16 h. To the reaction mixture were addedwater (50 mL) and ethyl acetate (50 mL). After the mixture was stirredvery well, the organic layer was separated and washed with water (50 mL)and brine (50 mL) subsequently. Solvent was removed; and the residualmaterial was purified on a silica-gel column (MeOH/DCM, 1/60 to 1/30),giving a di-Boc protected intermediate (1.3 g, 11.1%). This intermediate(1.3 g, 2.21 mmol, 1 eq.) was dissolved in DCM (13 mL). To the stirredsolution was added a solution of 4 M HCl in dioxane (1.3 mL); and themixture was stirred at r.t. for 1 h, and then evaporated to dryness,giving the title compound (0.75 g, 73.5%): ¹H NMR (D₂O, 500 MHz) δ ppm0.92 (t, 3H), 1.64 (q, 2H), 2.29 (q, 2H), 3.36-3.87 (m, 6H), 4.07 (d,0.45H), 3.20-3.34 (m, 3H), 3.47 (t, 0.4H), 4.47-4.61 (m, 3H), 5.19 (d,0.55H), 7.50 (s, 1H), 8.75 (s, 1H); ¹³C NMR (D₂O, 125 MHz) δ ppm 12.61,18.97, 25.00, 37.52, 37.93, 51.71, 53.85, 5636, 65.41, 68.97, 69.71,70.04, 70.25, 73.41, 90.84, 95.01, 118.31, 126.22, 134.36, 168.17,177.63, 177.87; m/z (ESI⁺) 386.7.

Example 14. Preparation of 2-N-butyryl-3,4,6-tri-O-acetyl-D-glucosamine(Compound 14)

To a mixture of compound 8 (4.17 g, 10 mmol, 1 eq.) in THF (60 mL) wasadded benzylamine (1.2 g, 11 mmol, 1.1 eq.). The mixture was stirred atr.t. for 16 h, followed by addition of water (50 mL) and ethyl acetate(50 mL) while stirring was continued. The organic layer was separated,washed with water (50 mL) and brine (50 mL). Solvent was removed byrotary evaporation, and the residual material was purified on asilica-gel column (EA/PE, 1/3 to 3/1), providing the title compound (3.0g, 80.0%): H NMR (CDCl₃, 500 MHz) δ ppm 0.89 (t, 3H), 1.54-1.61 (m, 2H),1.98 (s, 3H), 2.01 (s, 3H), 2.07 (s, 3H), 2.09-2.19 (m, 2H), 3.64-3.68(m, 0.2H), 3.94-3.99 (m, 0.2H), 4.08-4.12 (m, 1H), 4.17-4.29 (m, 2.4H),4.60-4.63 (m, 0.2H), 4.73 (d, 0.8H), 5.01-5.12 (m, 1.2H), 5.21-5.30 (m,1.6H), 5.59 (d, 0.2H), 5.96 (d, 0.8H), 6.34 (m, 0.2H); ¹³C NMR (CDCl₃,125 MHz) δ ppm 13.55, 13.68, 18.96, 20.73, 29.77, 38.36, 38.62, 52.27,56.95, 62.22, 67.56, 68.13, 68.42, 71.02, 91.68, 97.74, 169.44, 169.56,171.00, 171.10, 171.48, 172.28, 173.56, 176.56; m/z (ESI⁺) 375.8.

Example 15. Preparation of 2-N-1,3-di-O-tributyryl-D-glucosamine(Compound 15)

To a mixture of GlcNBu (10.0 g, 40 mmol, 1 eq.) in DMF (200 mL) wereadded (dimethoxymethyl)benzene (60.8 g, 400 mmol, 10 eq.) andp-toluenesulfonic acid monohydrate (0.76 g, 4 mmol, 0.1 eq.). Themixture was stirred at 50° C. for 16 h. After cooled to r.t., themixture was poured into water (800 mL) and stirred for 1 h. The solidmaterial was collected by filtration, washed with water (100 mL) andpet-ether (100 mL), and dried, giving4,6-O-benzalidene-2-N-butyryl-D-glucosamine (8.0 g, 59.0%). Thiscompound (3.37 g, 10 mmol, 1 eq.) was taken into pyridine (33 mL),followed by addition of DMAP (0.12 g, 1 mmol, 0.1 eq.) and butyricanhydride (3.95 g, 25 mmol, 2.5 eq.). The mixture was stirred at r.t.for 16 h, and then poured into water (330 mL). The resulting mixture wasstirred at r.t. for 1 h, and solid material was collected by filtration,washed with water (50 mL) and pet-ether (50 mL) subsequently, and dried,providing 4,6-O-benzylidene-1,2-di-O-2-N-butyryl-D-glucosamine (2.9 g,60.8%). The glucosamine derivative thus obtained (2.9 g, 6 mmol, 1 eq.)was added to DCM (58 mL), followed by addition of water (1 mL) andtrifluoroacetic acid (1 mL). The mixture was stirred at r.t. for 10 min,and then diluted with water (50 mL) and stirred briefly. The organiclayer was separated, washed with water (50 mL) and saturated aqueoussodium bicarbonate solution (50 mL). The organic layer was evaporated todryness; and the residual material was purified on a silica-gel column(MeOH/DCM, 1/40 to 1/20), giving the title compound (1.3 g, 55.0%): ¹HNMR (CD₃OD, 500 MHz) δ ppm 0.84-0.94 (m, 9H), 1.52-1.66 (m, 6H),2.04-2.42 (m, 6H), 3.44-3.82 (m, 4H), 3.92-4.24 (m, 1H), 5.04-5.17 (m,1H), 5.69-6.06 (m, 1H), 7.82-8.05 (m, 1H); ¹³C NMR (CD₃OD, 125 MHz) δppm 13.88, 13.94, 19.11, 19.20, 19.40, 36.67, 36.76, 36.95, 37.02,38.61, 48.48, 48.65, 48.83, 49.00, 49.17, 61.91, 69.25, 74.01, 75.99,76.35, 78.66, 91.89, 93.69, 173.35, 173.67, 174.76, 175.11, 176.42,176.50; m/z (ESI⁻) 387.9.

Example 16. Preparation of 2-N-4,6-O-tributyryl-D-glucosamine (Compound16)

4,6-O-benzalidene-2-N-butyryl-D-glucosamine (3.37 g, 10 mmol, 1 eq.) wasadded to DMF (50 mL). The mixture was cooled to −10° C. under nitrogenatmosphere, followed by batch-wise addition of NaH (oil dispersion, 1.08g, 27 mmol, 2.7 eq.). The temperature of the mixture was kept below 0°C. during the addition of NaH, and then increased to r.t. slowly. Afterstirring at r.t. for 2 h, the mixture was poured into water (300 mL).The resultant mixture was stirred at r.t. for 1 h. Solid material wascollected by filtration, washed with water (50 mL) and pet-ether (50 mL)subsequently, and dried, giving4,6-O-benzylidene-1,3-O-dibenzyl-2-N-butyryl-D-glucosamine (4.5 g,87.1%) as an intermediate. To this intermediate (4.5 g, 8.7 mmol, 1 eq.)was added DCM (90 mL), followed by addition of water (1.5 mL) andtrifuoroacetic acid (18 mL). The mixture was stirred at r.t. for 10 min,then diluted with water (50 mL), and stirred briefly. The organic layerwas separated, washed with water (50 mL) and saturated aqueous sodiumbicarbonate solution (50 mL). The organic layer was evaporated todryness; and the residual material was triturated with warm pet-ether,then collected by filtration and dried, providing1,3-O-dibenzyl-2-N-butyryl-D-glucosamine (3.2 g, 85.7%). This compound(2.5 g, 5.8 mmol, 1 eq.) was taken into pyridine (25 mL), followed byaddition of DMAP (0.04 g, 0.29 mmol, 0.05 eq.) and butyryl anhydride(2.3 g, 14.5 mmol, 2.5 eq.). After stirring at r.t. for 16 h, thereaction mixture was poured into water (250 mL) and then stirred at r.t.for 1 h. The insoluble material was collected, washed with water (50 mL)and pet-ether (50 mL), and dried, giving1,3-O-dibenzyl-2-N-4,6-di-O-tributyryl-D-glucosamine (2.9 g, 87.8%).Compound thus obtained (2.9 g) was taken into MeOH (15 mL), followed byaddition of palladium-carbon (10%, 1.45 g) and acetic acid (15 mL), andhydrogenolysized under hydrogen atmosphere (hydrogen balloon) for 48 h.The mixture was filtered, and the filtrate was concentrated to dryness.The residual material was purified on a silica-gel column (MeOH/DCM,1/100 to 1/30), giving the title compound (1.3 g, 65.6%): ¹H NMR (CD₃OD,500 MHz) δ ppm 0.78-1.03 (m, 9H), 1.52-1.66 (m, 6H), 2.18-2.31 (m, 6H),3.30 (s, 0.3H), 3.62 (s, 0.7H), 3.78-4.11 (m, 4.3H), 4.63 (s, 0.3H),4.86 (t, 1H), 5.07 (s, 0.8H); ¹³C NMR (CD₃OD, 125 MHz) δ ppm 12.67,17.97, 18.98, 35.46, 35.58, 37.51, 37.53, 37.92, 54.38, 54.46, 57.51,62.31, 69.00, 71.13, 71.49, 71.83, 91.17, 95.69, 172.87, 172.94, 173.55,173.63, 173.86, 175.13, 175.21, 175.62; m/z (ESI⁺) 389.8.

Example 17. Preparation of 2-N-butyryl-1,3-di-O-(L-valyl)-D-glucosaminehydrochloride (Compound 17)

To 4,6-O-benzylidene-2-N-butyryl-D-glucosamine (3.37 g, 10 mmol, 1 eq)in DMF (100 mL) were added N-Boc-L-valine (4.77 g, 22 mmol, 2.2 eq.),HOBt (4.05 g, 30 mmol, 3 eq.), EDCI (7.64 g, 40 mmol, 4 eq.), DIPEA(7.74 g, 60 mmol, 6 eq.). The mixture was stirred at r.t. for 16 h,followed by addition of water (50 mL) and ethyl acetate (50 mL). Themixture was stirred well; and organic layer was separated, washed withwater (50 mL) and brine (50 mL), and evaporated to dryness. The residualmaterial was purified on a silica-gel column (EA/PE, 1/6), providing1,3-O-bis(N-Boc-L-valyl)-2-N-butyryl-glucosamine (2.0 g, 27.2%). Thecompound obtained above (2.0 g, 2.7 mmol, 1 eq.) was dissolved in DCM(20 mL), followed by addition of 4 M HCl in dioxane (2 mL). The mixturewas stirred at r.t. for 1 h, and evaporated to dryness, giving the titlecompound (1.1 g, 77.5%): ¹H NMR (D₂O, 500 MHz) δ ppm 0.87-1.16 (m, 15H),1.55-1.60 (m, 2H), 2.22-2.58 (m, 4H), 3.63-4.01 (m, 4.5H), 4.17-4.27 (m,1.9H), 4.53 (d, 0.6H), 5.21-5.41 (m, 1H), 6.27 (s, 0.6H); ¹³C NMR (D₂O,125 MHz) δ ppm 12.79, 12.93, 16.30, 16.80, 17.11, 17.17, 17.42, 17.80,18.64, 18.89, 29.02, 29.23, 37.36, 37.63, 50.09, 51.61, 58.28, 67.33,68.05, 71.13, 73.91, 73.96, 91.03, 92.98, 168.75, 169.36, 171.87,177.34; m/z (ESI⁺) 448.2.

Example 18. Preparation of 2-N-3,4-O-tributyryl-D-glucosamine (Compound18)

To a mixture of GlcNBu (10 g, 40 mmol, 1 eq.) in toluene (100 mL) wereadded p-toluenesulfonic acid monohydrate (0.76 g, 4 mmol, 0.1 eq.) andbenzyl alcohol (60 mL). The mixture was refluxed, in a Dean-Starkapparatus to remove water, for 16 h. The mixture was cooled to r.t.,stirred, and followed by addition of pet-ether (30 mL). After stirredthoroughly, the solid material was collected, and re-dissolved in hotethyl acetate (100 mL). The hot ethyl acetate solution was cooled tor.t., and the solid material was collected and dried, giving1-O-benzyl-2-N-butyryl-D-glucosamine (4.0 g, 29.4%). This material (3.4g, 10 mmol, 1 eq.) was added into pyridine (50 mL). The mixture wascooled to 0° C. under nitrogen atmosphere, followed by addition of DMAP(0.12 g, 1 mmol, 0.1 eq.) and TBDMSCl (3.0 g, 20 mmol, 2 eq.),subsequently. The mixture was gradually warmed to 50° C., and stirred at50° C. for 12 h., and then cooled to r.t. The mixture was concentratedto dryness on a rotary evaporator; and the residual material waspurified on a silica-gel column (MeOH/DCM, 1/30), giving thecorresponding intermediate,1-O-benzyl-2-N-butyryl-6-O-(tert-butyldimethylsilyl-D-glucosamine, (2.0g, 44.5%). The intermediate (4.5 g, 10 mmol, 1 eq.) was added topyridine (50 mL), followed by addition of DMAP (0.12 g, 1 mmol, 0.1 eq.)and butyric anhydride (3.9 g, 25 mmol, 2.5 eq.). After stirred at r.t.overnight, the mixture was concentrated on a rotary evaporator. Theresidual material was purified on a silica-gel column (MeOH/DCM, 1/100),giving1-O-benayl-2-N-3,4-O-tributyryl-6-O-(tert-butyldimentylsilyl)-D-glucosamine(5.9 g, 99.8%). The compound obtained above (5.9 g, 10 mmol, 1 eq.) wasdissolved in methanol (50 mL) and acetic acid (50 mL), followed byaddition of Pd/C (10% palladium on carbon, 0.6 g), hydrogenolysizedunder hydrogen atmosphere (hydrogen balloon) for 48 h. The reactionmixture was filtered, and the filtrate was evaporated to dryness. Theresidual material was purified on a silica-gel column (MeOH/DCM, 1/60),giving the debenzylated intermediate (4.0 g, 79.8%). This intermediate(1.5 g, 3.0 mmol, 1 eq.) was taken into DCM (15 mL), followed byaddition of a solution of 4 M HCl in dioxane (1.5 mL). The mixture wasstirred at r.t. for 30 min, and evaporated to dryness, providing thetitle compound (1.1 g, 94.8%): ¹H NMR (CD₃OD, 500 MHz) δ ppm 0.89-0.97(m, 9H), 1.54-1.67 (m, 6H), 2.12-2.36 (m, 6H), 3.52-3.64 (m, 1.5H),4.03-4.25 (m, 2.2H), 4.39 (d, 0.5H), 4.97-5.09 (m, 1.4H), 5.19-5.36 (m,1H), 7.62-7.76 (m, 0.5H); ¹³C NMR (CD₃OD, 125 MHz) δ ppm 13.98, 19.30,19.39, 20.34, 36.86, 37.02, 37.09, 38.78, 53.50, 53.66, 62.08, 64.38,70.15, 70.61, 70.67, 72.41, 92.65, 92.82, 173.91, 174.66, 175.23,176.14; m/z (ESI⁺) 389.9.

Example 19. Preparation of 2-N-4-O-dibutyryl-6-O-(L-valyl)-D-glucosaminehydrochloride (Compound 19)

To a mixture of 1,3-O-dibenzyl-2-N-butyryl-D-glucosamine (4.29 g, 10mmol, 1 eq.) in DMF (50 mL) were added N-Boc-L-valine (2.6 g, 12 mmol,1.2 eq.), HOBt (4.05 g, 30 mmol, 3 eq.), EDCI (7.64 g, 40 mmol, 4 eq.),and DIPEA (7.74 g, 60 mmol, 6 eq.). The mixture was stirred at r.t. for16 h, followed by addition of water (50 mL) and ethyl acetate (50 mL)and stirred. The organic layer was separated, washed with water (50 mL)and brine (50 mL), subsequently. Solvent was removed, and the residualmaterial was purified on a silica-gel column (EA/PE, 1/6), providing1,3-O-dibenzyl-2-N-butyryl-6-O—(N-Boc-L-valyl)-D-glucosamine (2.4 g,35.5%). This compound (1.4 g, 2.2 mmol, 1 eq.) was taken into pyridine(14 mL), followed by addition of DMAP (0.02 g, 0.2 mmol, 0.1 eq.) andbutyric anhydride (0.53 g, 3.3 mmol, 1.5 eq.); and the mixture wasstirred at r.t. overnight. Solvent was removed on a rotary evaporator,the residual material was purified on a silica-gel column (MeOH/DCM,1/100), giving1,3-dibenzyl-2-N-4-O-dibutyryl-6-O—(N-Boc-L-valyl)-D-glucosamine (1.5 g,99.8%). The compound obtained above (1.7 g, 2.4 mmol, 1 eq.) was addedto a mixture of methanol (50 mL) and acetic acid (50 mL), followed byaddition of 10% palladium on carbon (0.2 g). The mixture was stirredunder hydrogen atmosphere for 48 h, then filtered. Solvent was removedby rotary evaporation; and the residual material was purified (silicagel column; eluent MeOH/DCM, 1/30), giving debenzylated intermediate(1.15 g, 91.2%). The intermediate (1.15 g, 2.2 mmol, 1 eq.) was treatedin DCM (15 mL) with a solution of 4 MHCl in dioxane (1.5 mL) at r.t. for30 min. The mixture was evaporated to dryness, giving the title compound(0.99 g, 98.1%): ¹H NMR (CD₃OD, 500 MHz) δ ppm 0.94-0.98 (m, 6H), 1.10(t, 6H), 1.62-1.67 (m, 4H), 2.22-2.38 (m, 5H), 3.67-6.97 (m, 3.2H),4.08-4.36 (m, 2.7H), 4.73 (d, 0.3H), 5.11 (d, 0.7H); ¹³C NMR (CD₃OD, 125MHz) δ ppm 13.94, 13.97, 18.18, 18.44, 19.33, 30.82, 36.88, 38.78,39.20, 55.75, 58.66, 59.51, 65.49, 68.28, 70.04, 72.33, 72.71, 92.51,96.96, 169.87, 174.47, 176.67, 177.17; m/z (ESI⁺) 420.0.

Example 20. Preparation of2-N-butyryl-3-O-(2-(4-isobutylphenyl)propanoyl)-D-glucosamine (Compound20)

1-O-benzyl-4,6-O-benzylidene-2-N-butyryl-D-glucosamine (4.27 g, 10 mmol,1 eq.) was added to DMF (50 mL), followed by addition of isobutyric acid(2.06 g, 10 mmol, 1 eq.), HOBt (4.05 g, 30 mmol, 1.5 eq.), EDCI (7.64 g,40 mmol, 2 eq.), and DIPEA (7.74 g, 60 mmol, 3 eq.). The mixture wasstirred at r.t. for 16 h. Water (50 mL) and ethyl acetate (50 mL) wereadded to the mixture, and stirred briefly. The organic layer wasseparated, washed with water (50 mL) and brine (50 mL), subsequently.Solvent was removed on a rotary evaporator, and the residual materialwas purified on a silica-gel column (MeOH/DCM, 1/50 to 1/40), providing1-O-benzyl-4,6-O-benzylidene-2-N-butyryl-3-O-(2-(4-isobutylphenyl)propanoyl)-D-glucosamine(5.0 g, 81.3%). This compound (6.1 g, 10 mmol, 1 eq.) was added to DCM(60 mL), followed by addition of water (2 mL) and trifluoroacetic acid(22 mL). The mixture was stirred at r.t. for 10 min, and then water (50mL) was added. The organic layer was separated, washed with water (50mL) and saturated aqueous then sodium bicarbonate, and evaporated todryness. The residual material was purified on a silica-gel column(MeOH/DCM, 1/100 to 1/30), giving1-O-benzyl-2-N-butyryl-3-O-(2-(4-isobutylphenyl)propanoyl)-D-glucosamine(5.1 g, 96.7%). The compound thus obtained (5.3 g, 10 mmol, 1 eq.) wasdissolved in methanol (25 mL), followed by addition of palladium oncarbon (10%, 2.0 g) and acetic acid (25 mL). The mixture washydrogenolysized under hydrogen atmosphere (balloon) for 48 h. Themixture was filtered, and the filtrate was evaporated to dryness. Theresidual material was purified on a silica-gel column (MeOH/DCM, 1/30 to1/10), providing the title compound (3.9 g, 89.2%): ¹H NMR (CDCl₃, 500MHz) δ ppm 0.83-0.87 (m, 9H), 1.41-1.52 (m, 5H), 1.76-1.84 (m, 1H),1.96-2.0 (m, 2H), 2.40-2.41 (m, 2H), 3.24-4.17 (m, 8H), 4.62-5.24 (m,2H), 5.64-6.07 (m, 1H), 6.31-6.59 (m, 1H), 7.05 (d, 2H), 7.15 (d, 2H);¹³C NMR (CDCl₃, 125 MHz) δ ppm 13.59, 18.86, 30.10, 38.17, 44.97, 52.23,61.99, 69.43, 71.57, 73.78, 91.44, 127.14, 129.37, 137.39, 140.69,174.04, 175.95; m/z (ESI⁺) 438.0.

Example 21. Preparation of 2-N-butyryl-3-O-(L-valyl)-D-glucosaminehydrochloride (Compound 21)

To N-Boc-L-valine (100 mg, 0.46 mmol, 1.1 eq.) in DMF (5 mL) were added1-O-benzyl-2-N-butyryl-4,6-O-isopropylidene-D-glucosamine (150 mg, 0.40mmol, 1 eq.), HOBt (65 mg, 0.48 mmol, 1.2 eq.), EDCI (115 mg, 0.60 mmol,1.5 eq.), and DIPEA (1 mL), subsequently. The mixture was stirred atr.t. overnight, diluted with ethyl acetate (50 mL). The mixture waswashed with water (3×50 mL), and concentrated to dryness. The residualmaterial was purified on a silica-gel column (MeOH/DCM, 1/30 to 1/10),providing an off-white solid (210 mg). This material (210 mg) wasdissolved in a mixture of methanol (20 mL), DCM (2 mL), and water (1mL). After addition of Pd(OH)₂/C (0.5 g), the mixture was stirred underhydrogen atmosphere at r.t. overnight. The mixture was filtered, and thefiltrate was evaporated to dryness. The residual material was taken intoDCM (5 mL) containing 1.50 mL solution of 4 M HCl in dioxane, andstirred at r.t. for 1 h. The solid material was collected by filtration,and dried under vacuum at 60° C., giving the title compound (90 mg,58.6%): ¹H NMR (CD₃OD, 500 MHz) δ ppm 0.93-0.97 (t, 3H), 1.03-1.32 (d,6H), 1.59-1.65 (m, 2H), 1.97-2.35 (m, 3H), 3.33-4.19 (m, 7.3H),5.02-5.36 (m, 2.2H); ¹³C NMR (CD₃OD, 125 MHz) δ ppm 12.66, 16.68, 17.08,18.77, 29.33, 37.51, 47.14, 48.16, 58.25, 68.57, 71.31, 76.13, 91.41,167.80, 168.71; m/z (ES⁺) 349.6, (ES⁻) 383.8.

Example 22. Preparation of2-N-butyryl-6-O-(2-(4-isobutylphenyl)propanoyl)-D-glucosamine (Compound22)

To a mixture of GlcNBu (1.25 g, 5 mmol, 1 eq.) in DMF (15 mL) wereadded, in sequence, HOBt (810 mg, 6 mmol, 1.2 eq.), EDCI (1.15 mg, 6mmol, 1.2 eq.), DIPEA (1 mL), and ibuprofen (1.24 g, 6 mmol, 1.2 eq.).The mixture was stirred at r.t. overnight, and evaporated to dryness.The residual material was purified on a silica gel column (MeOH/DCM,1/30 to 1/10), giving the title compound (523 mg, 23.9%): ¹H NMR (D₂O,500 MHz) δ ppm 0.80-0.95 (m, 9H), 1.38-1.44 (m, 3H), 1.54-1.66 (m, 2H),1.74-1.84 (m, 1H), 2.14-2.22 (t, 2H), 2.36-2.42 (d, 2H), 3.22-5.04 (m,8H), 7.01-7.20 (m, 4H); ¹³C NMR (D₂O, 125 MHz) δ ppm 12.59, 17.70,18.97, 30.00, 37.54, 44.63, 54.26, 63.58, 69.48, 70.85, 71.04, 71.09,91.19, 95.75, 126.90, 128.95, 137.89, 140.30, 175.03, 175.08, 175.11,175.77; m/z (ESI⁺) 438.0.

Example 23. Preparation of 2-N-3-O-dibutyryl-D-glucosamine (Compound 23)

1-O-Benzy-2-N-butyryl-D-glucosamine (3.4 g, 10 mmol, 1 eq.) was addedinto DMF (5 mL) and stirred, followed by addition of(dimethoxymethyl)benzene (6.1 g, 40 mmol, 4 eq.) and p-toluenesulfonicacid monohydrate (0.19 g, 1 mmol, 0.1 eq.). The mixture was stirred at50° C. for 16 h, cooled to r.t., and poured into water (80 mL). Themixture was stirred for 1 h, and the solid material was collected,washed with water and pet-ether (in sequence, 10 mL each), and dried,giving 1-O-benzyl-4,6-O-benzylidene-2-N-butyryl-D-glucosamine (4.1 g,96%). This compound (4.27 g, 10 mmol, 1 eq.) was dissolved in pyridine(50 mL), followed by addition of, while efficient stirring was applied,DMAP (0.12 g, 1 mmol, 0.1 eq.) and butyric anhydride (2.37 g, 15 mmol,1.5 eq.). After the completion of the addition, the mixture was stirredat r.t. for 16 h. The reaction mixture was poured into water (300 mL)and the mixture was stirred at r.t. for 1 h. The solid material wascollected, washed with water (50 mL) and then with pet-ether (50 mL),and dried, providing1-O-benzyl-4,6-O-benzylidene-2-N-3-O-dibutyryl-D-glucosamine (4.5 g,90.3%). This compound (3 g, 6 mmol, 1 eq.) was suspended in DCM (58 mL),followed by addition, while stirring was applied, of water (1 mL) andtrifluoroacetic acid (11 mL). The mixture was stirred at r.t. for 10min., and diluted with water (50 mL). The organic layer was separated,washed with water (50 mL) and saturated aqueous sodium bicarbonatesolution (50 mL), and evaporated to dryness. The residual material waspurified on a silica-gel column (MeOH/DCM, 1/100 to 1/30), giving1-O-benzyl-2-N-3-O-dibutyryl-D-glucosamine (2.1 g, 86.7%). The compoundthus obtained (2.1 g, 5.1 mmol, 1 eq.) was put in methanol (10 mL),followed by addition of palladium on carbon (10%, 1.05 g) and thenacetic acid (10 mL). The mixture was stirred under hydrogen atmospherefor 48 h. The mixture was filtered, and the filtrate was evaporated todryness. The residual material was purified on a silica-gel column(MeOH/DCM, 1/30 to 1/10), giving the title compound (0.45 g, 27.3%): ¹HNMR (CD₃OD, 500 MHz) δ ppm 0.90-0.95 (m, 6H), 1.54-1.65 (m, 4H),2.10-2.17 (m, 2H), 2.25-2.36 (m, 2H), 3.36-3.38 (m, 0.2H), 3.48-3.58 (m,1H), 3.67-3.81 (m, 2H), 3.85-3.90 (m, 1H), 4.05-4.10 (m, 0.8H), 4.59 (s,0.2H), 4.70 (d, 0.2H), 4.99 (t, 0.2H), 5.06 (d, 0.8H), 5.19-5.23 (m,0.8H), 7.60 (d, 0.8H), 8.0 (d, 0.1H); ¹³C NMR (CD₃OD, 125 MHz) δ ppm12.62, 17.99, 18.94, 35.63, 35.72, 37.47, 37.52, 47.12, 47.63, 52.32,61.01, 61.16, 68.50, 71.58, 73.40, 75.52, 76.48, 91.39, 95.27, 173.57,174.01, 174.72, 174.80, 174.88; m/z (ESI⁻) 320.0.

Example 24. Preparation of 2-N-butyryl-4,6-O-diisobutyryl-D-glucosamine(Compound 24)

2-N-Butyryl-1,3-O-dibenzyl-D-glucosamine (2.5 g, 5.8 mmol, 1 eq.) wastaken into pyridine (25 mL), followed by addition of DMAP (0.04 g, 0.29mmol, 0.05 eq.) and isobutyric anhydride (2.3 g, 14.5 mmol, 2.5 eq.).The mixture was stirred at r.t. for 16 h, and then poured into water(250 mL). After the mixture was stirred at r.t. for 1 h, the solidmaterial was collected, washed with water (50 mL) and then withpet-ether (50 mL), and dried, providing2-N-butyryl-1,3-O-dibenzyl-4,6-O-diisobutyryl-D-glucosamine (2.9 g,87.8%). This compound (2.9 g, 5.1 mmol, 1 eq.) was added into methanol(15 mL), followed by addition of Pd/C (10%, 1.45 g) and then acetic acid(15 mL). The mixture was stirred under a hydrogen atmosphere (hydrogenballoon) for 48 h. The mixture was filtered, and the filtrate wasevaporated to dryness. The residual material was purified on asilica-gel column (MeOH/DCM, 1/100 to 1/30), giving the title compound(1.3 g, 65.6%): ¹H NMR (CD₃OD, 500 MHz) δ ppm 0.94-0.98 (m, 3H),1.15-1.18 (m, 12H), 1.60-1.68 (m, 2H), 2.20-2.26 (m, 2H), 2.54-2.63 (m,2H), 3.63-4.18 (m, 5H), 4.55-4.69 (m, 0.2H), 4.91 (t, 1H), 5.11 (d,0.8H); ¹³C NMR (CD₃OD, 125 MHz) δ ppm 13.95, 19.25, 19.41, 20.28, 35.07,35.12, 38.86, 39.24, 55.85, 58.94, 63.62, 68.76, 70.39, 72.12, 72.48,73.27, 92.52, 96.99, 176.53, 177.52, 178.33; m/z (ESI⁺) 390.0.

Example 25. Preparation of 2-N-butyryl-4,6-O-dihexanoyl-D-glucosamine(Compound 25)

2-N-Butyryl-1,3-O-dibenzyl-D-glucosamine (2.5 g, 5.8 mmol, 1 eq.) wastaken into pyridine (25 mL), followed by addition of DMAP (0.04 g, 0.29mmol, 0.05 eq.) and hexanoic anhydride (3.1 g, 14.5 mmol, 2.5 eq.). Themixture was stirred at r.t. for 16 h, and then poured into water (250mL). After the mixture was stirred at r.t. for 1 h, the solid materialwas collected, washed with water (50 mL) and then with pet-ether (50mL), and dried, providing2-N-butyryl-1,3-O-dibenzyl-4,6-O-dihexanoyl-D-glucosamine (3.2 g,87.2%). This compound (3.2 g, 5.1 mmol, 1 eq.) was added into methanol(15 mL), followed by addition of Pd/C (10%, 1.6 g) and then acetic acid(15 mL). The mixture was stirred under a hydrogen atmosphere (hydrogenballoon) for 48 h. The mixture was filtered, and the filtrate wasevaporated to dryness. The residual material was purified on asilica-gel column (MeOH/DCM, 1/100 to 1/30), giving the title compound(1.9 g, 84.0%): ¹H NMR (CD₃OD, 500 MHz) δ ppm 0.86-0.94 (m, 6H),1.11-1.29 (m, 8H), 1.57-1.64 (m, 4H), 2.16-2.34 (m, 4H), 2.50-2.59 (m,0.5H), 3.34 (s, 1H), 3.60-4.18 (m, 4.2H), 4.67 (t, 0.2H), 4.88-5.12 (m,1.6H); ¹³C NMR (CD₃OD, 125 MHz) δ ppm 13.94, 14.24, 19.18, 20.35, 32.39,38.86, 38.91, 39.29, 55.79, 55.86, 63.68, 68.68, 68.83, 70.37, 72.57,72.89, 92.56, 97.08, 174.45, 175.18, 176.53, 176.62, 177.60, 178.42; m/z(ESI⁺) 446.2.

Example 26. Preparation of 2-N-6-O-dibutyryl-D-glucosamine (Compound 26)

Et₃N (1.0 g, 10 mmol, 1 eq) was added to a solution of butyric acid(0.88 g, 10 mmol, 1 eq) in THF (20 mL). The solution was cooled to 0° C.under N₂ atmosphere, followed by addition of 4-nitrobenzene-1-sulfonylchloride (2.2 g, 10 mmol, 1 eq). The reaction mixture was stirred atr.t. for 2 h. Et₃N (1.0 g, 10 mmol, 1 eq) was added to the reactionmixture, followed by addition of2-N-butyryl-1,3-di-O-benzyl-D-glucosamine (4.3 g, 10 mmol, 1 eq) andDMAP (0.12 g, 1 mmol, 1 eq). The mixture was stirred at r.t. for 16 h,and concentrated under reduced pressure. The residual material waspurified by flash column chromatography (eluent: MeOH/DCM=1/100˜1/30) toafford 2-N-3-O-dibutyryl-1,3-di-O-benzyl-D-glucosamine (3.5 g, 70.1%).Pd/C (10%, 1.7 g) was added to a solution of2-N-3-O-dibutyryl-1,3-di-O-benzyl-D-glucosamine (3.5 g, 7.0 mmol, 1 eq)in MeOH (17 mL), followed by addition of acetic acid (17 mL). Themixture was stirred at r.t. under H₂ atmosphere for 48 h. The mixturewas filtered. The filtration was concentrated under reduced pressure.The residual material was purified by flash column chromatography(eluent: MeOH/DCM=1/100˜1/30) to afford the title compound (2.1 g,94.2%); ¹H NMR (500 MHz, CD₃OD) δ ppm 0.98 (tdd, J=7.4, 5.4, 1.7 Hz,6H), 1.59-1.75 (m, 4H), 2.20-2.28 (m, 2H), 2.35 (t, J=7.6 Hz, 2H),3.42-3.35 (m, 1H), 3.67-3.77 (m, 1H), 3.87 (dd, J=10.8, 3.6 Hz, 1H),3.94-4.06 (m, 1H), 4.16-4.30 (m, 1H), 4.35-4.46 (m, 1H), 4.58-4.66 (d,J=8.4 Hz, 0.2H), 5.07-5.11 (d, J=3.6 Hz, 0.8H); m/z (ESI⁻): 318.0.

Example 27. Preparation of 2-N-4-O-dibutyryl-D-glucosamine (Compound 27)

Et₃SiH (11.2 g, 96.6 mmol, 10.0 eq) was added to a solution of1,3-di-O-benzyl-4,6-O-benzylidene-2-N-butyryl-D-glucosamine (5 g, 9.66mmol, 1 eq) in DCM (100 mL). The mixture was cooled to 0° C. under N₂atmosphere, followed by addition of BF₃-Et₂O (2.74 g, 19.320 mmol, 2.0eq). The mixture was stirred at r.t. for 16 h. DCM (100 mL) and H₂O (100mL) were added to the reaction mixture. The organic layer was washedwith H₂O (100 mL) and brine (100 mL), and concentrated under reducedpressure. The residual material was purified by flash columnchromatography (eluent: MeOH/DCM=1/100˜1/50) to afford1,3,6-tri-O-benzyl-2-N-butyryl-D-glucosamine (3.0 g, 60%). Butyricanhydride (1 g, 6.351 mmol, 1.1 eq) and DMAP (35 mg, 0.289 mmol, 0.05eq) were added to a solution of1,3,6-tri-O-benzyl-2-N-butyryl-D-glucosamine (3 g, 5.773 mmol, 1 eq) inpyridine (30 mL). The mixture was stirred at 35° C. for 16 h. Themixture was concentrated under reduced pressure. The residual materialwas purified by flash column chromatography (eluent: EA/PE=1/50˜1/10) toafford 1,3,6-tri-O-benzyl-2-N-4-O-dibutyryl-D-glucosamine (1.85 g,54.4%). AcOH (9.25 mL) was added to a solution of1,3,6-tri-O-benzyl-2-N-4-O-dibutyryl-D-glucosamine (1.85 g, 3.137 mmol,1 eq) in MeOH (9.25 mL), followed by addition of 10% Pd/C (1.4 g). Themixture was stirred at 35° C. under H₂ atmosphere for 72 h. The mixturewas filtered. The filtration was concentrated under reduced pressure.The residual material was purified by flash column chromatography(eluent: MeOH/DCM=1/100˜1/30) to afford the title compound (920 mg,92%); ¹H NMR (500 MHz, CD₃OD) δ ppm 0.92-1.09 (m, 6H), 1.59-1.80 (m,4H), 2.16-2.56 (m, 4H), 3.51-3.66 (m, 2H), 3.84-3.94 (m, 1H), 3.95-4.07(m, 2H), 4.70 (d, J=8.0 Hz, 0.07H), 4.81-4.89 (m, 1H), 5.18 (d, J=3.5Hz, 1H); ¹³C NMR (125 MHz, CD₃OD) δ ppm 12.54, 17.98, 18.97, 35.60,37.46, 54.46, 57.55, 61.14, 68.99, 69.71, 71.99, 91.06, 173.26, 175.14;m/z (ESI⁺) 320.0.

Example 28. Preparation of2-N-butyryl-1-O-(2-(4-hydroxyphenyl)ethyl)-D-glucosamine (Compound 30)

Acetic anhydride (20.4 g, 200 mmol, 5 eq) was added to a solution of2-N-butyryl-D-glucosamine (10 g, 40 mmol, 1 eq) in pyridine (50 mL), andthe mixture was stirred at r.t. overnight. The mixture was evaporated invacuo and purified by flash column chromatography (eluent: DCM) toafford 1,3,4,6-tetra-O-acetyl-2-N-butyryl-D-glucosamine (14.5 g, 87.0%).Phenylmethanamine (70 mL) was added to a solution of1,3,4,6-tetra-O-acetyl-2-N-butyryl-D-glucosamine (14.5 g, 35 mmol, 1 eq)in THF (70 mL) in drop-wise at 0° C. The mixture was stirred at 0° C.for 2 h and concentrated in vacuo. The residue was purified by flashcolumn chromatography (eluent: EA/PE=1/30˜1/2) to afford3,4,6-tri-O-acetyl-2-N-butyryl-D-glucosamine (5.6 g, 43.1%). A solutionof 3,4,6-tri-O-acetyl-2-N-butyryl-D-glucosamine (5.2 g, 13.8 mmol, 1 eq)in DCM (26 mL) was cooled to 0° C. under N₂ atmosphere. DBU (0.42 g, 2.7mmol, 0.2 eq) was added to the reaction mixture followed by addition of2,2,2-trichloroacetonitrile (7.0 g, 48.3 mmol, 3.5 eq). The reactionmixture was stirred at r.t. for 3 h and concentrated in vacuo. Theresidue was purified by flash column chromatography (eluent:MeOH/DCM=0/100˜1/100) to afford3,4,6-tri-O-acetyl-2-N-butyrylamino-2-deoxy-D-glucopyranosyltrichloroacetimidate (5.2 g, 72.2%). 4-(2-Hydroxyethyl)phenyl acetate(0.87 g, 4.8 mmol, 1 eq) was added to a solution of3,4,6-tri-O-acetyl-2-N-butyrylamino-2-deoxy-D-glucopyranosyltrichloroacetimidate (2.5 g, 4.8 mmol, 1 eq) in DCM (100 mL). Thereaction mixture was cooled to −20° C. under N₂ atmosphere. The mixturewas stirred at −20° C. for 2 h and concentrated in vacuo. The residuewas purified by flash column chromatography (eluent: EA/PE=1/10˜1/1) toafford2-N-butyryl-3,4,6-tri-O-acetyl-1-O-(2-(4-acetoxyphenyl)ethyl-D-glucosamine(500 mg, 19.4%). MeONa (50.4 mg, 0.9 mmol, 1 eq) was added to a solutionof2-N-butyryl-3,4,6-tri-1-acetyl-1-O-(2-(4-acetoxyphenyl)ethyl)-D-glucosamine(500 mg, 0.9 mmol, 1 eq) in MeOH (5 mL). The reaction mixture wasstirred at r.t. for 2 h and concentrated in vacuo. The residue waspurified by flash column chromatography (eluent: MeOH/DCM=1/10˜1/5) toafford the title compound (300 mg, 87.0%). ¹H NMR (400 MHz, CD₃OD) δ ppm1.0 (t, J=7.0 Hz, 3H), 1.64-1.69 (m, 2H), 2.18 (t, J=7.5 Hz, 2H), 2.78(t, J=5.0 Hz, 2H), 3.28-3.32 (m, 1H), 3.47 (t, J=8.8 Hz, 1H), 3.61-3.73(m, 3H), 3.90 (d, J=12.0 Hz, 1H), 4.06-4.10 (m, 1H), 4.45 (d, J=8.2 Hz,1H), 6.70 (d, J=7.3 Hz, 2H), 7.05 (d, J=7.3 Hz, 2H); ¹³C NMR (125 MHz,CD₃OD) δ ppm 12.78, 18.80, 34.02, 37.89, 55.22, 60.73, 69.98, 70.57,73.77, 75.79, 100.93, 115.18, 130.07, 130.83, 153.66, 177.26; m/z(ESI⁺): 369.9.

Example 29. Preparation of2-N-butyryl-6-O-(2-hydroxybenzoyl)-D-glucosamine (Compound 41)

Potassium carbonate (50.78 g, 651 mmol, 3 eq) was added to a solution of2-hydroxybenzoic acid (30 g, 217 mmol, 1 eq) in acetone (300 mL),followed by addition of (bromomethyl)benzene (37.15 g, 217 mmol, 1 eq).The mixture was stirred at 50° C. for 16 h. The mixture was filtered andconcentrated under reduced pressure. The residual material was purifiedby flash column chromatography (eluent: EA/PE=1/10˜1/1) to afford benzyl2-(benzyloxy)benzoate (24 g, 34.7% yield). H₂O (10 mL) was added to asolution of benzyl 2-(benzyloxy)benzoate (20 g, 62.8 mmol, 1 eq) andNaOH (7.54 g, 188.5 mmol, 1 eq) in ethanol (100 mL). The reactionmixture was stirred at 80° C. for 16 h. The mixture was concentratedunder reduced pressure. H₂O (50 mL) was added to the mixture. Theaqueous phase was washed with DCM (50 mL×3) and 1N HCl was added to theaqueous phase to adjust pH to 4; and the aqueous phase was washed withDCM (50 mL×3). The organic layer was washed by brine (50 mL), and dried(Na₂SO₄). The organic layer was concentrated under reduced pressure toafford 2-(benzyloxy)benzoic acid (13 g, 92.8% yield) as a yellow solid.Di(1H-imidazol-1-yl)methanone (12.87 g, 79.4 mmol, 1.1 eq) was added toa solution of 2-(benzyloxy)benzoic acid (16.5 g, 72.3 mmol, 1 eq) in THF(200 mL) under N₂. The mixture was stirred at 25° C. for 1 h. Theorganic layer was concentrated under reduced pressure, purified by flashcolumn chromatography (eluent: EA/PE=1/10˜1/1) to afford(2-(benzyloxy)phenyl)(1H-imidazol-1-yl)methanone (12.5 g, 60% yield) asan oil. The mixture of 1,3-di-O-benzyl-2-N-butyryl-D-glucosamine (17.52g, 40.8 mmol, 1 eq) and DBU (1.24 g, 8.14 mmol, 0.2 eq) in MeCN (200 mL)was stirred at 50° C. for 20 min under N₂, followed by addition of(2-(benzyloxy)phenyl)(1H-imidazol-1-yl)methanone (12.5 g, 45 mmol, 1.1eq). The mixture was stirred at 50° C. for 16 h, concentrated underreduced pressure. The residual material was purified by flash columnchromatography (eluent: MeOH/DCM=1/100-3/100) to afford1,3-di-O-benzyl-6-(2-benzyloxybenzoyl)-2-N-butyryl-D-glucosamine (17.3g, 66.28% yield) as a white solid. To the solution of the compound (3.5g, 5.4 mmol, 1 eq) obtained above in MeOH (25 mL) and AcOH (25 mL) wasadded Pd/C (2 g, 10%, wet) under H₂. The mixture was stirred at 25° C.for 32 h. The mixture was filtered and concentrated under reducedpressure. The residual material was purified by flash columnchromatography (eluent: MeOH/DCM=1/100˜1/30) to afford the titlecompound (1.05 g, 50% yield) as a white solid. ¹H NMR (500 MHz, CD₃OD) δppm 1.00 (t, J=7.0 Hz, 3H), 1.70 (dt, J=14.5, 7.5 Hz, 2H), 2.28 (t,J=6.5 Hz, 2H), 3.53 (t, J=9.0 Hz, 1H), 3.58-4.25 (m, 3H), 4.51-4.64 (m,1H), 4.69 (d, J=11.5 Hz, 1H), 4.72-5.55 (m, 1H), 6.97 (dd, J=20.5 Hz, 8Hz, 2H), 7.53 (t, J=7 Hz, 1H), 7.96 (d, J=7.5 Hz, 1H). ¹³C NMR (125 MHz,CD₃OD) δ ppm 175.69, 175.17, 169.74, 161.35, 135.46, 129.79, 118.88,116.97, 112.26, 95.77, 91.31, 74.45, 73.84, 71.25, 71.08, 70.86, 69.32,64.18, 64.06, 57.24, 54.34, 37.91, 37.50, 18.95, 12.54. m/z (ESI⁺):369.9.

Example 30. Preparation of6-O-(1-admantaneacetyl)-2-N-butyryl-D-glucosamine (Compound 56)

Et₃N (1.0 g, 10 mmol, 1 eq) was added to a solution of 1-adamantylaceticacid (1.94 g, 10 mmol, 1 eq) in THF (20 mL). The solution was cooled to0° C. under N₂ atmosphere, followed by addition of4-nitrobenzene-1-sulfonyl chloride (2.2 g, 10 mmol, 1 eq). The reactionmixture was stirred at r.t. for 2 h. Et₃N (1.0 g, 10 mmol, 1 eq) wasadded to the reaction mixture, followed by addition of2-N-butyryl-1,3-di-O-benzyl-D-glucosamine (4.3 g, 10 mmol, 1 eq) andDMAP (0.12 g, 1 mmol, 1 eq). The mixture was stirred at r.t. for 16 h,and concentrated under reduced pressure. The residual material waspurified by flash column chromatography (eluent: MeOH/DCM=1/100˜1/30) toafford 6-O-(1-admantaneacetyl)-2-N-butyryl-1,3-di-O-benzyl-D-glucosamine(4.6 g, 76.3%). 10% Pd/C (2.3 g) was added to a solution of6-O-(1-admantaneacetyl)-2-N-butyryl-1,3-di-1-benzyl-D-glucosamine (4.6g, 7.6 mmol, 1 eq) in MeOH (23 mL), followed by addition of acetic acid(23 mL). The mixture was stirred at r.t. under H₂ atmosphere for 48 h.The mixture was filtered. The filtration was concentrated under reducedpressure. The residual material was purified by flash columnchromatography (eluent: MeOH/DCM=1/100˜1/30) to give the title compound(2.4 g, 75.0%); ¹H NMR (400 MHz, CD₃OD) δ ppm 0.99 (t, J=7.5 Hz, 3H),1.65-1.80 (m, 14H), 1.98-2.28 (m, 7H), 3.34-4.48 (m, 6.2H), 5.11 (d,J=3.1 Hz 0.8H); ¹³C NMR (125 MHz, CD₃OD) δ ppm 12.57, 18.98, 28.69,32.38, 36.35, 36.43, 37.50, 41.91, 42.07, 48.51, 54.29, 62.90, 69.37,71.04, 71.13, 91.22, 172.05, 175.12; m/z (ESI⁺): 426.0.

Example 31. Preparation of4,6-di-O-butyryl-2-N-(butyryl-_(d7))-D-glucosamine (Compound 68)

Following the same procedure in Example 16, the title compound wasprepared. ¹H NMR (CD₃OD, 500 MHz) δ ppm 0.78-1.03 (m, 6H), 1.52-1.66 (m,4H), 2.18-2.31 (m, 4H), 3.30 (s, 0.3H), 3.62 (s, 0.7H), 3.78-4.11 (m,4.3H), 4.63 (s, 0.3H), 4.86 (t, 1H), 5.07 (s, 0.8H); ¹³C NMR (CD₃OD, 125MHz) δ ppm 13.96, 19.33, 36.83, 36.94, 55.75, 58.90, 62.25, 63.80,70.34, 72.50, 72.88, 73.46, 92.56, 97.06, 174.35, 175.07, 176.66; m/z(ESI⁺) 397.1.

Example 32. Preparation of 4,6-O-benzylidene-2-N-butyryl-D-glucosamine(Compound 72)

(Dimethoxymethyl)benzene (30.5 g, 200.594 mmol, 10 eq) was added to asolution of GlcNBu (5.0 g, 20.059 mmol, 1 eq) in DMF (50 mL), followedby addition of p-toluenesulfonic acid monohydrate (0.191 g, 1.003 mmol,0.05 eq). The reaction mixture was stirred at 50° C. for 16 h. Themixture was cooled to r.t., and poured into H₂O (250 mL). The mixturewas stirred at r.t. for 1 h. The solid was filtered, then washed withH₂O (50 mL) and PE (100 mL), and dried to afford the title compound(5.22 g, 77.0%); H NMR (500 MHz, CD₃OD) δ ppm 0.93-1.09 (m, 3H),1.62-1.80 (m, 2H), 2.20-2.38 (m, 2H), 3.34 (s, 1H), 3.53-3.62 (m, 1H),3.74-3.87 (m, 1H), 3.97 (t, J=9.5 Hz, 1H), 4.01-4.10 (m, 1H), 4.18-4.39(m, 1H), 4.76 (d, J=7.5 Hz, 0.19H), 5.17 (d, J=3.0 Hz, 1H), 5.65 (s,1H), 7.35-7.47 (m, 4H), 7.55-7.57 (m, 2H).

Example 33. Preparation of6-O-isopropyloxycarbonyl-2-N-butyryl-D-glucosamine (Compound 73)

GlcNBu (2.49 g, 10 mmol, 1.0 eq) was dissolved in pyridine (25 mL),cooled to 0° C. under N₂ atmosphere. To the cold solution was addedisopropyl carbonochloridate (1.2 g, 10 mmol, 1.0 eq). The reactionmixture was stirred at r.t. overnight, and concentrated in vacuum. Theresidual material was purified by flash column chromatography (eluent:MeOH/DCM=1/100˜1/20) to afford the title compound (2.01 g, 60.0%); ¹HNMR (CD₃OD, 500 MHz) δ ppm 0.99 (t, J=7.5 Hz, 3H), 1.30 (d, J=6.5 Hz,6H), 1.65-1.72 (m, 2H), 2.26 (t, J=7.2 Hz, 2H), 3.38 (t, J=9.4 Hz, 1H),3.74 (t, J=9.4 Hz, 1H), 3.88-3.91 (m, 1H), 4.00-4.03 (m, 1H), 4.27-4.30(m, 1H), 4.41-4.4 (m, 1H), 4.83-4.90 (m, 1H), 5.11 (d, J=3.4 Hz, 1H);¹³C NMR (CD₃OD, 125 MHz) δ ppm 12.56, 13.05, 18.97, 20.57, 37.48, 54.25,66.54, 69.33, 71.04, 71.64, 91.20, 154.89, 175.13; m/z (ESI⁺): 335.9.

Example 34. Preparation of 2-N-1,4,6-tri-O-tetrabutyryl-D-glucosamine(Compound 74)

Imidazole (3.18 g, 46.785 mmol, 2.0 eq) was added to a solution of1-O-benzyl-4,6-O-benzylidene-2-N-butyryl-D-glucosamine (10.0 g, 23.392mmol, 1.5 eq) in DMF (100 mL). The mixture was cooled to 0° C. under N₂atmosphere, followed by addition of TBSCl (5.29 g, 35.089 mmol, 1.5 eq).The reaction mixture was stirred at r.t. for 16 h. Ethyl acetate (100mL) and H₂O (100 mL) were added to reaction mixture. The organic layerwas washed with H₂O (100 mL) and brine (100*3 mL), and concentratedunder reduced pressure. The residual material was purified by flashcolumn chromatography (eluent: EA/PE=1/20˜1/5) to afford1-O-benzyl-4,6-O-benzylidene-3-O-(tert-butyldimethylsilyl)-2-N-butyryl-D-glucosamine(10.0 g, 78.9%). PtO₂ (3 g) was added to a solution of1-O-benzyl-4,6-O-benzylidene-3-O-(tert-butyldimethylsilyl)-2-N-butyryl-D-glucosamine(10 g, 18.459 mmol, 1 eq) in MeOH (100 mL). The mixture was stirred at30° C. under H₂ atmosphere for 48 h. The mixture was filtered. Thefiltration was concentrated under reduced pressure. The residualmaterial was purified by flash column chromatography (eluent:MeOH/DCM=1/50˜1/10) to afford3-O-(tert-butyldimethylsilyl)-2-N-butyryl-D-glucosamine (4.8 g, 71.6%).Butyric anhydride (6.89 g, 43.574 mmol, 3.3 eq) and DMAP (81 mg, 0.660mmol, 0.05 eq) were added to a solution of3-O-(tert-butyldimethylsilyl)-2-N-butyryl-D-glucosamine (4.8 g, 13.204mmol, 1.0 eq) in pyridine (48 mL). The mixture was stirred at 35° C. for16 h. The mixture was concentrated under reduced pressure. The residualmaterial was purified by flash column chromatography (eluent:EA/PE=1/20˜1/5) to afford3-O-(tert-butyldimethylsilyl)-1,4,6-tri-O-2-N-tetrabutyryl-D-glucosamine(6.5 g, 85.8%). The obtained compound (6.5 g, 11.328 mmol, 1 eq) wasdissolved in DCM (65 mL), followed by addition of 4M HCl in 1,4-dioxane(6.5 mL). The mixture was stirred at r.t. for 16 h, and concentratedunder reduced pressure. The residual material was purified by flashcolumn chromatography (eluent: MeOH/DCM=1/100˜1/50) to afford the titlecompound (4.5 g, 86.5%); ¹H NMR (500 MHz, CD₃OD) δ ppm 0.87-1.08 (m,12H), 1.57-1.78 (m, 8H), 2.15-2.52 (m, 8H), 3.86-3.94 (m, 1H), 3.98-4.05(m, 1H), 4.05-4.13 (m, 1H), 4.13-4.19 (m, 1H), 4.19-4.29 (m, 1H), 5.02(t, J=10.0 Hz, 1H), 6.21 (d, J=3.5 Hz, 1H), 8.21 (d, J=8.0 Hz, 0.25H);¹³C NMR (125 MHz, CD₃OD) δ ppm 12.52, 12.59, 17.86, 17.92, 18.91, 19.41,35.21, 35.36, 35.43, 37.24, 37.86, 53.00, 53.46, 61.82, 68.57, 70.07,70.65, 89.90, 171.90, 172.69, 173.42, 175.27; m/z (ESI⁺) 481.9 (M+Na).

Example 35. Preparation of 1-O-benzyl-2-N-butyryl-D-glucosamine(Compound 75)

AcCl (21.4 g, 272.808 mmol, 3.4 eq) was added to a solution of GlcNBu(20.0 g, 80.238 mmol, 1.0 eq) in BnOH (200 mL). The reaction mixture wasstirred at r.t. for 0.5 h, then at 70° C. for 2 h. The mixture wasconcentrated under vacuum pressure. EtOH (200 mL) was added, and themixture was stirred for 0.5 h. The mixture was filtered, and dried toafford the title compound (4.7 g). The filtration was concentrated to100 mL under reduced pressure, followed by addition of iPr₂O (200 mL).The mixture was stirred for 0.5 h, and the second crop of the titlecompound (15.21 g) was obtained (by filtration and drying). The totalyield was 73.1%. ¹H NMR (500 MHz, CD₃OD) δ ppm 0.97 (t, J=7.5 Hz, 3H),1.51-1.78 (m, 2H), 2.23 (t, J=7.5 Hz, 2H), 3.09 (dd, J=10.5, 3.5 Hz,0.19H), 3.38-3.47 (m, 1H), 3.67-3.81 (m, 3H), 3.81-3.91 (m, 2H), 3.95(dd, J=11.0, 3.5 Hz, 1H), 4.53 (d, J=12.0 Hz, 1H), 4.78 (d, J=12.0 Hz,1H), 5.36 (d, J=3.5 Hz, 0.14H), 7.18-7.54 (m, 5H); ¹³C NMR (125 MHz,CD₃OD) δ ppm 12.63, 18.97, 37.43, 53.88, 54.82, 60.82, 61.32, 68.68,70.03, 70.37, 71.03, 71.19, 71.95, 72.68, 89.40, 96.10, 127.44, 127.94,127.98, 137.52, 175.08; m/z (ESI⁻) 337.9.

Example 36. Preparation of 2-N-butyryl-1,3-di-O-benzyl-D-glucosamine(Compound 76)

BnBr (11.15 g, 65.210 mmol, 2.2 eq) was added to a solution of4,6-O-benzylidene-2-N-butyryl-D-glucosamine (10.0 g, 29.641 mmol, 1.0eq) in DMF (150 mL). The mixture was cooled to −10° C. under N₂atmosphere, followed by addition of NaH (3.2 g, 80.031 mmol, 2.7 eq, 60%in mineral oil). The reaction mixture was stirred at r.t. for 2 h. EA(200 mL) and H₂O (200 mL) were added to the reaction mixture. Theorganic layer was washed with H₂O (100 mL) and brine (100×3 mL), andconcentrated under reduced pressure. The residual material was purifiedby flash column chromatography (eluent: EA/PE=1/100˜1/50) to afford4,6-O-benzylidene-2-N-butyryl-1,3-di-O-benzyl-D-glucosamine (11.5 g,75.0%). H₂O (3.45 mL) was added to a solution of4,6-O-benzylidene-2-N-butyryl-1,3-di-O-benzyl-D-glucosamine (11.5 g,22.217 mmol, 1.0 eq) in TFA (46 mL). The mixture was stirred at r.t. for1 h, then added into H₂O (115 mL). The mixture was stirred for 0.5 h,filtered and the filter cake was added into saturated sodium bicarbonate(115 mL). The mixture was stirred for 0.5 h, filtered and the filtercake was added into EA (11.5 mL) and PE (115 mL). The mixture wasstirred at 50° C. for 1 h, filtered and the filter cake was dried toafford the title compound (6.1 g, 64%); ¹H NMR (500 MHz, CD₃OD) δ ppm0.87-0.98 (m, 3H), 1.54-1.67 (m, 2H), 2.07-2.23 (m, 2H), 3.52-3.65 (m,1H), 3.71-3.83 (m, 3H), 3.85-4.01 (m, 1H), 4.07-4.18 (m, 1H), 4.52-4.60(m, 1H), 4.63-4.74 (m, 1H), 4.81 (d, J=12.0 Hz, 1H), 4.86 (d, J=3.5 Hz,1H), 4.92 (s, 1H), 7.24-7.49 (m, 10H), 8.10 (d, J=9.0 Hz, 0.15H); ¹³CNMR (125 MHz, CD₃OD) δ ppm 12.63, 18.97, 37.43, 53.88, 54.82, 60.82,61.32, 68.68, 70.03, 70.37, 71.03, 71.19, 71.95, 72.68, 89.40, 96.10,127.44, 127.94, 127.98, 137.52, 175.08; m/z (ESI⁺) 430.1.

Example 37. Preparation of2-N-butyryl-3-O-cyclohexylaminocarbonyl-6-O-(4-cyclohexaylamino-4-oxo-butyryl)-D-glucosamine(Compound 77)

DMAP (0.12 g, 1 mmol, 0.1 eq) was added to a solution of2-N-butyryl-1,3-di-O-benzyl-D-glucosamine (4.3 g, 10 mmol, 1 eq) inpyridine (43 mL), followed by addition of dihydrofuran-2,5-dione (1.0 g,10 mmol, 1 eq). The reaction mixture was stirred at r.t. for 16 h, andconcentrated under reduced pressure. The residual material was purifiedby flash column chromatography (eluent: MeOH/DCM=1/20˜1/10) to afford2-N-butyryl-1,3-di-O-benzyl-6-O-(4-hydroxy-4-oxo-butyryl)-D-glucosamine(3.0 g, 56.7%). DCC (1.4 g, 6.8 mmol, 1.2 eq) was added to a solution of2-N-butyryl-1,3-di-O-benzyl-6-O-(4-hydroxy-4-oxo-butyryl)-D-glucosamine(3.0 g, 5.7 mmol, 1.0 eq) in DCM (30 mL), the mixture was stirred atr.t. for 16 h, and concentrated under reduced pressure. The residualmaterial was purified by flash column chromatography (eluent:MeOH/DCM=1/100˜1/40) to afford2-N-butyryl-1,3-di-O-benzyl-4-O-cyclohexylaminocarbonyl-6-O-(4-cyclohexylamino-4-oxo-butyryl)-D-glucosamine(3.0 g, 73.0%). 10% Pd/C (1.5 g) was added to a solution of theabove-obtained compound (3.0 g, 4.1 mmol, 1 eq) in MeOH (15 mL),followed by addition of acetic acid (15 mL). The mixture was stirred atr.t. under H₂ atmosphere for 48 h. The mixture was filtered. Thefiltration was concentrated under reduced pressure. The residualmaterial was purified by flash column chromatography (eluent:MeOH/DCM=1/100˜1/30) to afford the title compound (2.0 g, 88.5%); ¹H NMR(CD₃OD, 500 MHz) δ ppm 0.95 (t, J=7.0 Hz, 3H), 1.11-1.99 (m, 21H), 2.01(s, 2H), 2.66-2.68 (m, 4H), 3.33-4.60 (m, 8.44H), 5.08 (s, 0.78H), 7.76(s, 0.57H), 8.23 (s, 0.76H); ¹³C NMR (CD₃OD, 125 MHz) δ ppm 12.64,19.00, 24.63, 28.77, 37.52, 37.57, 50.36, 50.48, 51.00, 54.19, 63.85,69.28, 70.84, 71.07, 71.17, 91.22, 95.77, 154.25, 154.33, 170.08,173.02, 175.09, 175.17, 175.71; m/z (ESI⁺): 556.3.

Example 38. Preparation of 2-N-butyryl-4,6-di-O-pentanoyl-D-glucosamine(Compound 78)

Pentanoic anhydride (2.23 g, 12 mmol, 3 eq) was added to a solution of2-N-butyryl-1,3-di-O-benzyl-D-glucosamine (2 g, 4 mmol, 1 eq) and DMAP(0.025 g, 0.2 mmol, 0.05 eq) in pyridine (10 mL). The mixture wasstirred at 35° C. for 16 h. Pyridine was removed under reduced pressure.The residue was dissolved by ethyl alcohol (30 mL), and added to H₂O(150 mL), and the solid was collected and dried, giving2-N-butyryl-1,3-di-O-benzyl-4,6-di-O-pentanoyl-D-glucosamine (2.3 g, 92%yield), as a light yellow solid. The above-obtained compound (2.3 g, 4mmol, 1 eq) was dissolved in MeOH (10 mL) and AcOH (10 mL), and thesolution was added to Pd/C (1.2 g, 10%, wet) under H₂. The mixture wasstirred at 25° C. for 40 h. The mixture was filtered and concentratedunder reduced pressure. The residual material was purified by flashcolumn chromatography (eluent: MeOH/DCM=1/100˜1/30) to afford the titlecompound (1 g, 60% yield). ¹H NMR (500 MHz, CD₃OD) δ 5.15 (s, 0.82H),4.70 (s, 0.16H), 4.26-4.03 (m, 3H), 3.99 (d, J=10.3 Hz, 1H), 3.89 (t,J=9.7 Hz, 1H), 3.70 (s, 0.48H), 2.50-2.34 (m, 4H), 2.26 (d, J=6.7 Hz,2H), 1.77-1.57 (m, 6H), 1.41 (s, 4H), 0.98 (d, J=7.1 Hz, 9H). ¹³C NMR(125 MHz, CD₃OD) δ 175.13, 173.79, 173.05, 95.66, 91.15, 72.05, 71.47,71.07, 68.94, 67.27, 62.41, 57.50, 54.36, 37.88, 37.44, 33.35, 33.23,26.61, 21.84, 18.95, 12.66, 12.53. m/z (ESI⁺) 417.9.

Example 39. Preparation of2-N-butyryl-4,6-di-O-(4-hydroxy-4-oxo-butyryl)-D-glucosamine (Compound79)

The dihydrofuran-2,5-dione (3 g, 30 mmol, 3 eq) was added to a solutionof 2-N-butyryl-1,3-di-1-benzyl-D-glucosamine (4.29 g, 10 mmol, 1 eq) andDMAP (0.06 g, 0.5 mmol, 0.05 eq) in pyridine (22 mL). The mixture wasstirred at 35° C. for 16 h. Pyridine was removed under reduced pressure.The residual material was purified by flash column chromatography(eluent: MeOH/DCM=1/100˜1/20) to afford2-N-butyryl-1,3-di-O-benzyl-4,6-di-O-(4-hydroxy-4-oxo-butyryl)-D-glucosamine(1.6 g, 25.8% yield) as a white solid. The above-obtained compound (1.5g, 2 mmol, 1 eq) was dissolved in MeOH (10 mL) and AcOH (10 mL),followed by addition of Pd/C (0.75 g, 10%, wet) under H₂. The mixturewas stirred at 25° C. for 40 h. The mixture was filtered andconcentrated under reduced pressure. The residual material was purifiedby flash column chromatography (eluent: MeOH/DCM=1/100˜1/10) to affordtitle compound (0.518 g, 57.68% yield) as a white solid. ¹H NMR (500MHz, CD₃OD) δ 5.16 (s, 0.81H), 4.71 (d, J=6.0 Hz, 0.19H), 4.19 (t,J=16.4 Hz, 3H), 3.99 (s, 1H), 3.93 (t, J=9.6 Hz, 1H), 3.73 (s, 1H), 3.65(s, 0.45H), 2.65 (t, J=20.7 Hz, 9H), 2.27 (d, J=6.3 Hz, 2H), 1.69 (d,J=6.5 Hz, 2H), 1.37 (d, J=34.1 Hz, 2H), 1.00 (s, 3H). ¹³C NMR (126 MHz,CD₃OD) δ 175.16, 174.85, 172.60, 172.10, 91.10, 72.04, 68.86, 67.12,62.89, 62.85, 54.22, 48.45, 37.90, 37.45, 31.66, 29.34, 28.82, 28.67,28.59, 28.45, 22.33, 18.97, 13.04, 12.54. m/z (ESI⁺) 449.9, m/z (ESI⁻)447.9.

Example 40. Preparation of 2-O-butyryl-4,6-di-O-propanoyl-D-glucosamine(Compound 80)

Propionic anhydride (1.56 g, 12 mmol, 3 eq) was added to a solution ofN-butyryl-1,3-di-O-benzyl-D-glucosamine (2 g, 4 mmol, 1 eq) and DMAP(0.025 g, 0.2 mmol, 0.05 eq) in pyridine (10 mL). The mixture wasstirred at 35° C. for 16 h. Pyridine was removed under reduced pressure.The residue was dissolved by ethyl alcohol (30 mL), and added to H₂O(150 mL), the solid was collected and dried to affordN-butyryl-1,3-di-O-benzyl-4,6-di-O-propanoyl-D-glucosamine (1.5 g, 65%yield) as a white solid. This white solid (1.5 g, 2 mmol, 1 eq) wasdissolved in MeOH (7.5 mL) and AcOH (7.5 mL), followed by addition ofPd/C (0.75 g, 10%, wet) under H₂. The mixture was stirred at 25° C. for40 h. The mixture was filtered and concentrated under reduced pressure.The residual material was purified by flash column chromatography(eluent: MeOH/DCM=1/100˜1/30) to afford the title compound (0.596 g,82.54% yield) as a white solid. ¹H NMR (500 MHz, CD₃OD) δ 5.16 (d, J=3.4Hz, 0.87H), 4.95 (d, J=9.8 Hz, 1H), 4.71 (d, J=7.8 Hz, 0.09H), 4.25 (dd,J=12.1, 4.6 Hz, 1H), 4.16 (m, 1H), 4.08 (dd, J=12.1, 2.2 Hz, 1H), 4.00m, 1H), 3.94-3.87 (m, 1H), 2.49-2.36 (m, 4H), 2.27 (t, J=7.4 Hz, 2H),1.69 (dd, J=14.8, 7.4 Hz, 2H), 1.17 (td, J=7.6, 3.8 Hz, 6H), 1.04-0.94(m, 3H). ¹³C NMR (126 MHz, CD₃OD) δ 175.14, 174.47, 173.82, 91.15,71.56, 68.91, 67.30, 62.42, 54.33, 37.44, 26.91, 26.77, 18.96, 12.53,7.93, 7.91. m/z (ESI⁺) 361.9.

Example 41. Preparation of 2-N-(butyryl-_(d7))-D-glucosamine (Compound81)

To a suspension of glucosamine hydrochloride (2.5 g, 11.59 mmol, 1 eq)in pyridine (50 mL), HMDS (24.2 mL, 115.9 mmol, 10 eq) was addedfollowed by TMSCl (14.7 mL, 115.9 mmol, 10 eq). The resulting mixturewas stirred at r.t. for 3 h. The mixture was evaporated in vacuo andpurified by flash column chromatography (eluent: EA/PE=1/30˜1/10) toafford 1,3,4,6-tetra-O-trimethylsilyl-D-glucosamine (4.0 g, 85.6%).Butyric-_(d7) acid (0.771 g, 8.1 mmol, 1 eq) was added to a solution of1,3,4,6-tetra-O-trimethylsilyl-D-glucosamine (3.8 g, 8.1 mmol, 1 eq) inDCM (38 mL), followed by addition of DCC (2.01 g, 9.7 mmol, 1.2 eq). Themixture was stirred at r.t. for 3 h. The mixture was evaporated in vacuoand purified by flash column chromatography (eluent: EA/PE=1/30˜1/15) toafford 2-N-butyryl-1,3,4,6-tetra-O-trimethylsilyl-D-glucosamine (3.0 g,67.8%). The above-obtained compound (3.0 g, 5.5 mmoL, 1 eq) wasdissolved in DCM (30 mL), followed by addition of 4 M HCl in Dioxane (1mL). The mixture was stirred at r.t. for 3 h and concentrated in vacuoto give the title compound (1.4 g, 99.9%); H NMR (400 MHz, D₂O) δ ppm3.38-3.50 (m, 1.67H), 3.61-3.87 (m, 4.63H), 4.65 (d, J=8.0 Hz, 0.4H),5.14 (d, J=3.0 Hz, 0.6H); ¹³C NMR (125 MHz, D₂O) δ ppm 53.94, 56.50,60.57, 60.72, 69.90, 70.12, 70.52, 71.53, 90.85, 94.96, 177.64, 177.87;m/z (ESI⁻): 255.0.

Example 42. Preparation of6-O-(4-aminobutyryl)-2-N-butyryl-D-glucosamine hydrochloride (Compound82)

4M HCl/dioxane (0.8 mL, 3.2 mmol, 2 eq) was added to a solution of6-O-(4-tert-butyloxycarbonylaminobutyryl)-2-N-butyryl-D-glucosamine (700mg, 1.6 mmol, 1 eq) in dioxane (15 mL). The mixture was stirred at r.t.for 3 h, some solid appeared, and the solvent was removed. The residualmaterial was dissolved with water and dried at −40° C. under vacuum togive the title compound (400 mg, 67.1%); ¹H NMR (500 MHz, D₂O) δ 5.13(d, J=3.5 Hz, 0.35H), 4.47-4.22 (m, 1.35H), 4.07-3.93 (m, 0.42H), 3.84(dd, J=10.6, 3.2 Hz, 1.02H), 3.72 (dd, J=10.7, 9.1 Hz, 1.18H), 3.67-3.54(m, 1.25H), 3.56-3.32 (m, 1.45H), 3.00 (s, 2H), 2.53 (d, J=2.3 Hz, 2H),2.22 (d, J=6.9 Hz, 2H), 2.00-1.81 (m, 2H), 1.56 (d, J=7.3 Hz, 2H), 0.85(dt, J=11.5, 5.7 Hz, 3H); ¹³C NMR (125 MHz, D₂O) δ 177.81, 177.56,176.90, 174.60, 95.02, 90.92, 73.51, 73.27, 70.36, 70.11, 69.84, 69.23,63.49, 62.51, 60.62, 56.42, 55.32, 53.89, 38.68, 37.94, 37.53, 30.53,21.96, 18.97, 12.62; m/z (ESI⁻) 370.9.

Example 43. Preparation of6-O-(4-aminobutyryl)-2-N-4-O-dibutyrl-D-glucosamine hydrochloride(Compound 83)

Butyric anhydride (2 g, 12.6 mmol, 3.15 eq) was added to a solution of6-O-(4-tert-butoxyaminobutyryl)-1,3-di-1-benzyl-2-N-butyryl-D-glucosamine(3 g, 4.9 mmol, 1 eq) and DMAP (25 mg, 0.2 mmol, 0.05 eq) in pyridine(30 mL). The mixture was stirred at r.t. for 16 h, pyridine was removedand dissolved with DCM, the organic layer washed with water andsaturated sodium bicarbonate solution, and dried with anhydrousmagnesium sulfate. The organic layer was concentrated under reducedpressure. The residual material was purified by flash columnchromatography (eluent: MeOH/DCM=1/100˜1/50) to afford6-O-(4-tert-butoxyaminobutyryl)-1,3-di-O-benzyl-2-N-4-O-dibutyryl-D-glucosamine(3 g, 89%). The compound thus obtained (3 g, 8.1 mmol, 1 eq) wasdissolved in MeOH (15 mL) and acetic acid (15 mL), followed by additionof Pd/C (10%, 1.2 g). The mixture was stirred at r.t. under H₂atmosphere for 48 h. The mixture was filtered. The filtration wasconcentrated under reduced pressure. The residual material was purifiedby flash column chromatography (eluent: MeOH/DCM=1/100˜1/50) to afford6-O-(4-tert-butoxyaminobutyryl)-2-N-4-O-dibutyryl-D-glucosamine (2 g,90%). This Boc derivative (1 g, 2 mmol, 1 eq) was dissolved in DCM (40mL), followed by addition of 4M HCl/dioxane (1 mL, 4 mmol, 2 eq). Themixture was stirred at r.t. for 3 h, some solid appeared, and thesolvent was removed. The residual material was dissolved with water anddried at −40° C. under vacuum to give the title compound (380 mg,43.4%); ¹H NMR (500 MHz, D₂O) δ 5.19 (d, J=3.0 Hz, 0.62H), 4.92 (t,J=9.4 Hz, 0.9H), 4.31 (td, J=12.9, 3.1 Hz, 0.98H), 4.21 (d, J=10.1 Hz,0.61H), 4.12 (dd, J=27.3, 12.6 Hz, 0.94H), 3.97-3.88 (m, 1.23H), 3.85(d, J=9.7 Hz, 0.32H), 3.78-3.69 (m, 0.69H), 3.02 (t, J=7.5 Hz, 2H),2.60-2.48 (m, 2H), 2.38 (dd, J=9.1, 5.1 Hz, 2H), 2.24 (t, J=7.2 Hz, 2H),2.04-1.84 (m, 2H), 1.67-1.45 (m, 4H), 0.95-0.76 (m, 6H); ¹³C NMR (125MHz, D₂O) δ 177.84, 177.61, 175.71, 174.32, 95.15, 90.97, 71.45, 71.20,70.58, 70.24, 68.40, 67.16, 62.38, 56.43, 53.83, 38.65, 37.92, 37.51,35.69, 30.53, 21.94, 18.96, 17.89, 12.77, 12.57; m/z (ESI⁻) 440.8.

Example 44. Preparation of6-O-(4-tert-butoxycarbonylaminobutyryl)-2-N-butyryl-D-glucosamine(Compound 84)

Triethylamine (15 mL, 108 mmol, 1.25 eq) was added to a solution of4-aminobutanoic acid (9 g, 87 mmol, 1 eq) and (BOC)₂O (20.9 g, 96 mmol,1.1 eq) in MeOH (200 mL). The mixture was stirred at 50° C. for 2 h. andsolvent was removed under reduced pressure. The residual material waspurified by flash column chromatography (eluent: MeOH/DCM=1/50˜1/5) toafford 4-((tert-butoxycarbonylamino)butanoic acid (9.0 g, 75%).4-((tert-Butoxycarbonyl)amino)butanoic acid (8 g, 39.4 mmol, 2 eq) wasadded to a solution of 1,3-di-O-benzyl-2-N-butyryl-D-glucosamine (8.5 g,19.7 mmol, 1 eq) in DMF (200 mL), followed by addition of HOBt (8 g,159.2 mmol, 3 eq), EDCI (15 g, 78.2 mmol, 4 eq), DIPEA (15 g, 116 mmol,6 eq). The mixture was stirred at r.t. for 16 h. H₂O (500 mL) were addedto the reaction mixture. The white suspension was filtered, and thefilter cake washed with water, then dried at 50° C. under vacuum to give1,3-di-1-benzyl-6-O-(4-tert-butoxycarbonylaminobutyryl)-2-N-butyryl-D-glucosamine(11 g, 45%). The above-obtained compound (5 g, 8.1 mmol, 1 eq) wasdissolved in MeOH (25 mL), followed by addition of acetic acid (25 mL),and then Pd/C (10%, 2.5 g). The mixture was stirred at r.t. under H₂atmosphere for 48 h. The mixture was filtered. The filtration wasconcentrated under reduced pressure. The residual material was purifiedby flash column chromatography (eluent: MeOH/DCM=1/100˜1/30) to affordthe title compound (3.07 g, 86%); ¹H NMR (500 MHz, CD₃OD) δ 5.53 (s,0.48H), 5.13 (s, 0.93H), 4.42 (d, J=11.7 Hz, 0.96H), 4.35-4.19 (m,0.96H), 4.04 (s, 0.93H), 3.90 (d, J=10.6 Hz, 0.93H), 3.75 (t, J=9.6 Hz,0.96H), 3.40 (t, J=6.8 Hz, 1H), 3.12 (d, J=5.5 Hz, 2H), 2.42 (t, J=6.3Hz, 2H), 2.27 (t, J=6.3 Hz, 2H), 1.90-1.76 (m, 2H), 1.69 (dd, J=13.7,6.7 Hz, 2H), 1.48 (s, 9H), 1.01 (d, J=7.1 Hz, 3H); ¹³C NMR (125 MHz,CD₃OD) δ 175.13, 173.51, 157.13, 95.74, 91.21, 78.58, 74.45, 73.87,71.25, 71.07, 70.90, 69.28, 63.54, 57.25, 54.32, 53.39, 39.22, 37.50,30.86, 27.37, 24.90, 18.95, 12.55; m/z (ESI⁺) 435.0, (ESI⁻) 433.0.

Example 45. Preparation of 4,6-di-O-acetyl-2-N-butyryl-D-glucosamine(Compound 85)

DMAP (0.04 g, 0.29 mmol, 0.05 eq) was added to a solution of1,3-di-O-benzyl-2-N-butyryl-D-glucosamine (2.5 g, 5.8 mmol, 1 eq) inpyridine (25 mL), followed by addition of acetic anhydride (1.5 g, 14.5mmol, 2.5 eq). The reaction mixture was stirred at r.t. for 16 h, andpoured into H₂O (250 mL). The mixture was stirred at r.t. for 1 h. Thesolid was filtered, then washed with H₂O (50 mL) and PE (50 mL), anddried to afford4,6-di-O-acetyl-1,3-di-O-benzyl-2-N-butyryl-D-glucosamine (3.2 g,87.2%). The compound thus obtained (3.2 g, 5.1 mmol, 1 eq) was dissolvedin MeOH (15 mL) and acetic acid (15 mL), followed by addition of Pd/C(10%, 1.6 g). The mixture was stirred at r.t. under H₂ atmosphere for 48h. The mixture was filtered. The filtration was concentrated underreduced pressure. The residual material was purified by flash columnchromatography (eluent: MeOH/DCM=1/100˜1/30) to afford the titlecompound (1.5 g, 88.9%); ¹H NMR (CD₃OD, 500 MHz) δ ppm 0.95 (t, J=7.0Hz, 3H), 1.60-1.67 (m, 2H), 2.04 (s, 3H), 2.08 (s, 3H), 2.23 (t, J=7.0Hz, 2H), 3.65-3.72 (m, 0.44H), 3.86 (t, J=9.5 Hz, 0.87H), 3.94-4.21 (m,3.82H), 4.66 (d, J=7.5 Hz, 0.16H), 4.86 (t, J=9.5 Hz, 1H), 5.11 (d,J=3.0 Hz, 0.85H), 7.84 (d, J=8.5 Hz, 0.6H); ¹³C NMR (CD₃OD, 125 MHz) δppm 13.94, 20.30, 20.71, 20.92, 38.80, 38.85, 39.23, 55.60, 55.68,58.68, 63.88, 68.88, 70.20, 72.82, 73.01, 73.22, 92.45, 96.98, 171.87,171.96, 172.48, 172.58, 176.48, 176.56; m/z (ESI⁺): 333.9.

Example 46. Preparation of2-N-butyryl-6-O-(9-hydroxy-9-oxononanoyl)-D-glucosamine (Compound 86)

BnBr (4.54 g, 26.565 mmol, 1.0 eq) and DBU (4.04 g, 26.565 mmol, 1.0 eq)were added to a solution of nonanedioic acid (5.0 g, 26.565 mmol, 1.0eq) in THF (30 mL) at 0° C. under N₂ atmosphere. The mixture was stirredat r.t. for 16 h. Ethyl acetate (50 mL) and H₂O (50 mL) were added toreaction mixture. The organic layer was washed with H₂O (50 mL) andbrine (50 mL), and concentrated under reduced pressure. The residualmaterial was purified by flash column chromatography (eluent:MeOH/DCM=1/100˜1/50) to afford 9-(benzyloxy)-9-oxononanoic acid (5.2 g,70.4%). 9-(benzyloxy)-9-oxononanoic acid (4.9 g, 17.604 mmol, 1.0 eq) inanhydrous THF (10 mL) was added to a solution of Et₃N (1.78 g, 35.209mmol, 1.0 eq) and NosCl (3.9 g, 19.604 mmol, 1.0 eq) in anhydrous THF(150 mL) at 0° C. under N₂ atmosphere. The mixture was stirred at r.t.for 2 h. Et₃N (1.78 g, 35.209 mmol, 1.0 eq), DMAP (430 mg, 3.521 mmol,0.2 eq) and 1,3-di-O-benzyl-2-N-butyryl-D-glucosamine (7.56 g, 17.604mmol, 1.0 eq) were added to the mixture. The reaction mixture wasstirred at r.t. for 16 h. Et₂O (200 mL) and H₂O (200 mL) were added tothe reaction mixture. The organic layer was washed with H₂O (200 mL) and1 M sodium hydroxide solution (100*2 mL), dried by anhydrous sodiumsulfate and concentrated under reduced pressure. The residual materialwas purified by flash column chromatography (eluent:MeOH/DCM=1/100˜1/50) to afford1,3-di-1-benzyl-2-N-butyryl-6-O-(9-benzyloxy-9-oxononanoyl)-D-glucosamine(7.4 g, 61.2%). The above-obtained compound (3.5 g, 5.074 mmol, 1 eq)was dissolved in MeOH (35 mL) and AcOH (35 mL), followed by addition ofPd/C (10%, 4.41 g). The mixture was stirred at 35° C. under H₂atmosphere for 48 h. The mixture was filtered. The filtration wasconcentrated under reduced pressure. The residual material was purifiedby flash column chromatography (eluent: MeOH/DCM=1/100˜1/50) to affordthe title compound (898 mg, 20.4%); ¹H NMR (500 MHz, CD₃OD) δ ppm 1.01(t, J=7.5 Hz, 3H), 1.41 (s, 6H), 1.57-1.77 (m, 6H), 2.28 (t, J=7.5 Hz,2H), 2.34 (t, J=7.5 Hz, 2H), 2.40 (t, J=7.5 Hz, 2H), 3.41 (t, J=9.5 Hz,1H), 3.76 (t, J=9.0 Hz 1H), 3.86-3.98 (m, 1H), 3.98-4.11 (m, 1H), 4.26(dd, J=11.5, 5.0 Hz, 1H), 4.43 (d, J=10.0 Hz, 1H), 5.13 (d, J=3.5 Hz,1H), 7.81 (d, J=8.5 Hz, 1H); ¹³C NMR (125 MHz, CD₃OD) δ ppm 13.96,20.36, 25.94, 26.01, 30.02, 34.92, 34.95, 38.91, 55.71, 64.76, 68.53,70.75, 72.48, 72.58, 92.62, 175.50, 176.54, 177.72; m/z (ESI⁻): 418.0.

Example 47. Preparation of 2-N-butyryl-6-O-phosphono-D-glucosamine(Compound 87)

GlcNBu (2.49 g, 10 mmol, 1.0 eq) was dissolved in pyridine (25 mL), andthis solution was cooled to −10° C. under N₂ atmosphere. To thissolution was added diphenyl phosphorochloridate (2.68 g, 10 mmol, 1.0eq). The reaction mixture was stirred at r.t. for 2-4 h, andconcentrated in vacuum. The residual material was purified by flashcolumn chromatography (eluent: MeOH/DCM=1/100˜1/30) to afford2-N-butyryl-6-O-(diphenylphosphono)-D-glucosamine (1.6 g, 73%). Theabove-obtained compound (1.6 g, 3.3 mmol, 1 eq) was dissolved in water(32 mL), followed by addition of Pt₂O (0.16 g). The mixture was stirredat r.t. under H₂ atmosphere for 48 h. The mixture was filtered. Thefiltration was concentrated under reduced pressure to afford the titlecompound (1.09 g, 99.2%); ¹H NMR (D₂O, 500 MHz) δ ppm 0.77-0.81 (m, 3H),1.47-1.51 (m, 2H), 2.13-2.17 (m, 2H), 3.38-3.47 (m, 1.6H), 3.58 (t,J=9.0 Hz, 0.4H), 3.65 (t, J=9.5 Hz, 0.6H), 3.77-4.09 (m, 3.4H), 4.62 (d,J=8.0 Hz, 0.4H), 5.01 (d, J=3.0 Hz, 0.6H); ¹³C NMR (D₂O, 125 MHz) δ ppm12.55, 18.88, 37.44, 37.84, 53.79, 56.36, 64.70, 69.35, 69.57, 70.23,70.34, 90.86, 94.93, 177.46, 177.74; ³¹P NMR (D₂O, 200 MHz) δ ppm 1.02;m/z (ESI⁻): 327.9.

Example 48. Preparation of 2-N-3,6-di-O-tributyryl-D-glucosamine(Compound 88)

Butyric anhydride (2.70 g, 17.034 mmol, 1.1 eq) and DMAP (95 mg, 0.774mmol, 0.05 eq) were added to a solution of1-O-benzyl-4,6-O-benzylidene-D-glucosamine (6.62 g, 15.486 mmol, 1.0 eq)in pyridine (66 mL). The mixture was stirred at 35° C. for 16 h. Themixture was concentrated under reduced pressure. The residual materialwas purified by flash column chromatography (eluent: EA/PE=1/20˜1/5) toafford 1-O-benzyl-4,6-O-benzylidene-2-N-3-O-dibutyryl-D-glucosamine (6.2g, 80.5%). This compound (7.93 g, 15.937 mmol, 1.0 eq) was placed in TFA(31.7 mL), followed by addition of H₂O (2.4 mL). The mixture was stirredat r.t. for 5 min, then added into saturated sodium bicarbonate (150mL). The mixture was stirred for 10 min, extracted by DCM (100 mL×3).The combined organic layer was washed with brine (100 mL), andconcentrated under reduced pressure. The residual material was purifiedby flash column chromatography (eluent: MeOH/DCM=1/100˜1/50) to afford1-O-benzyl-2-N-3-O-dibutyryl-D-glucosamine (5.5 g, 84.2%). Butyric acid(646 mg, 7.327 mmol, 1.0 eq) in anhydrous THF (2 mL) was added to asolution of Et₃N (741 mg, 7.327 mmol, 1.0 eq) and NosCl (1.62 g, 7.327mmol, 1.0 eq) in anhydrous THF (60 mL) at 0° C. under N₂ atmosphere. Themixture was stirred at r.t. for 2 h. Et₃N (741 mg, 7.327 mmol, 1.0 eq),DMAP (179 mg, 1.465 mmol, 0.2 eq) and1-O-benzyl-2-N-3-O-dibutyryl-D-glucosamine (3 g, 7.327 mmol, 1.0 eq)were added to the mixture. The reaction mixture was stirred at r.t. for16 h. Et₂O (100 mL) and H₂O (100 mL) were added to reaction mixture. Theorganic layer was washed with H₂O (200 mL) and 1 M sodium hydroxidesolution (100*2 mL), dried by anhydrous sodium sulfate and concentratedunder reduced pressure. The residual material was purified by flashcolumn chromatography (eluent: MeOH/DCM=1/100˜1/50) to afford1-O-benzyl-2-N-3,6-di-O-tributyryl-D-glucosamine (1.35 g, 38.5%). Thecompound thus obtained (1.35 g, 2.805 mmol, 1 eq) was dissolved in MeOH(7 mL), followed by addition of AcOH (7 mL), and then Pd/C (10%, 2.20g). The mixture was stirred at 35° C. under H₂ atmosphere for 48 h. Themixture was filtered. The filtration was concentrated under reducedpressure. The residual material was purified by flash columnchromatography (eluent: MeOH/DCM=1/100˜1/50) to afford the titlecompound (741.5 mg, 67.9%); ¹H NMR (500 MHz, CD₃OD) δ ppm 0.88-1.06 (m,9H), 1.55-1.77 (m, 6H), 2.12-2.25 (m, 2H), 2.27-2.45 (m, 4H), 3.59 (t,J=9.5 Hz, 1H), 3.79-3.87 (m, 0.14H), 4.05-4.17 (m, 2H), 4.28 (dt,J=11.5, 5.0 Hz, 1H), 4.38-4.50 (m, 1H), 4.75 (d, J=8.0 Hz, 0.14H), 5.07(d, J=3.5 Hz, 1H), 5.26 (t, J=10.5 Hz, 1H), 7.67 (d, J=9.0 Hz, 0.44H);¹³C NMR (125 MHz, CD₃OD) δ ppm 12.53, 12.58, 17.98, 18.02, 18.92, 35.46,35.69, 37.44, 52.25, 62.97, 68.75, 69.26, 73.14, 91.41, 173.84, 174.73;m/z (ESI⁺): 390.0.

Example 49. Preparation of2-N-butyryl-4-O-(D-glucopyranosy)-D-glucosamine (Compound 89)

Acetic anhydride (34.27 g, 340 mmol, 6 eq) was added to a solution ofD-glucose (10 g, 5.6 mmol, 1 eq) and DMAP (0.69 g, 0.056 mmol, 0.1 eq)in pyridine (150 mL). The mixture was stirred at 20° C. for 16 h.Pyridine was removed under reduced pressure. The residue was washed byPE (150 mL), and the solid was collected and dried to give1,2,3,4,6-pentaacetyl-D-glucopyranose (12 g, 55% yield) as a whitesolid. Phenylmethanamine (2.866 g, 26.8 mmol, 1.1 eq) was added to asolution of 1,2,3,4,6-penta-O-acetyl-D-glucopyranose (9.5 g, 24.4 mmol,1 eq) in THF (40 mL). The mixture was stirred at 25° C. for 25 h. Themixture was concentrated under reduced pressure and purified by flashcolumn chromatography (eluent: MeOH/DCM=1/100˜1/70) to afford2,3,4,6-tetra-O-acetyl-D-glucopyranose (9 g) as an oil. This compound(9.5 g, 27.3 mmol, 1 eq) was dissolved in DCM (100 mL), followed byaddition of DBU (0.831 g, 5.46 mmol, 0.2 eq) at 0° C. for 10 min, then2,2,2-trichloroacetonitrile (11.23 g, 98.2 mmol, 3.6 eq), drop-wise. Themixture was stirred at 25° C. for 3 h, then concentrated under reducedpressure. The residual material was purified by flash columnchromatography (eluent: MeOH/DCM=1/100˜1/70) to afford2,3,4,6-tetra-O-acetyl-D-glucopyranosyl trichloroacetimidate (8.5 g, 63%yield) as an oil. The solution of BF₃ in ether (1.695 g, 12 mmol, 2 eq)was drop added to the solution of2-N-butyryl-1,3,6-tri-O-benzyl-D-glucosamine (3.102 g, 5.97 mmol, 1 eq)and 2,3,4,6-tetra-O-acetyl-D-glucopyranosyl trichloroacetimidate (4.4 g,8.96 mmol, 1.5 eq) in DCM (100 mL). The mixture was stirred at 25° C.for 1 h, and then the pH of the mixture was adjusted to 7. The mixturewas then washed by brine (30 mL×3), and dried by Na₂SO₄. The organicphase was concentrated under reduced pressure and purified by flashcolumn chromatography (eluent: MeOH/DCM=1/100˜1/100) to afford thecorresponding disaccharide derivative (2.5 g, 50% yield) as a whitesolid. This disaccharide derivative (2.45 g, 2.88 mmol, 1 eq) wasdissolved in MeOH (25 mL) and AcOH (25 mL). To the solution was addedPd/C (1 g, 10%, wet) under H₂. The mixture was stirred at 25° C. for 16h. The mixture was filtered and concentrated under reduced pressure. Theresidual material was purified by flash column chromatography (eluent:MeOH/DCM=1/100˜1/20) to afford2-N-butyryl-4-O-(2,3,4,5-tetra-O-acetyl-D-glucopyranosyl)-D-glucosamine(0.5 g, 31% yield) as a white solid. To a solution of this intermediatecompound (0.5 g, 0.86 mmol, 1 eq) in MeOH (10 mL) was added sodiummethoxide (0.023 g, 0.43 mmol, 0.5 eq). The mixture was stirred at 25°C. for 16 h, then concentrated under reduced pressure. The residualmaterial was dissolved in H₂O (1.5 mL), and stirred with acidic ionexchange resin. The mixture was filtered and the filtrate wasconcentrated under reduced pressure, affording the title compound (0.26g, 73% yield). ¹H NMR (500 MHz, D₂O) δ 5.23 (s, 0.49H), 5.15 (s, 0.14H),5.07 (s, 0.09H), 4.67-4.48 (m, 1H), 4.38 (s, 0.12H), 4.18 (dd, J=9.5,5.0 Hz, 0.14H), 3.99 (d, J=10.5 Hz, 1H), 3.93 (d, J=14.0 Hz, 3H),3.90-3.82 (m, 0.68H), 3.81-3.68 (m, 3H), 3.62 (s, 0.42H), 3.59-3.47 (m,2H), 3.47-3.41 (m, 1H), 3.34 (q, J=11.0, 3.0 Hz, 1H), 2.49-2.11 (m, 2H),1.64 (q, J=14.0, 7.0 Hz, 2H), 1.09-0.72 (m, 3H). ¹³C NMR (125 MHz, D₂O)δ 178.64, 177.72, 177.49, 102.56, 94.84, 92.86, 90.53, 79.21, 78.82,76.40, 75.96, 75.47, 75.11, 74.78, 73.16, 72.31, 71.56, 70.71, 70.21,69.43, 69.05, 67.47, 60.54, 59.92, 56.18, 53.69, 52.61, 37.95, 37.52,18.95, 12.59. m/z (ESI⁻) 410.

Example 50. Preparation of 2-N-butyryl-6-¹⁸O-D-glucosamine (Compound 90)

Triphenylphosphine (667 mg, 2.54 mmol, 1.2 eq) was added to a solutionof 2-N-butyryl-1,3,4-tri-O-benzyl-D-glucosamine (1.12 g, 2.2 mmol, 1 eq)and benzoic-¹⁸O₂ acid (0.325 g, 2.58 mmol, 1.2 eq) in THF (50 mL),followed by addition of DEAD (0.44 g, 2.53 mmol, 1.2 eq). The mixturewas stirred at r.t. for 16 h. Then the mixture was concentrated underreduced pressure. The residual material was purified by flash columnchromatography (eluent: MeOH/DCM=1/200) to afford6-¹⁸O-6-O-(¹⁸O-benzoyl)-2-N-butyryl-1,3,4-tri-1-benzyl-D-glucosamine(1.2 g, 86.8%) with 98.7% abundance of ¹⁸O-isotope at 6-O-position andbenzoyl oxygen. This isotope-labelled intermediate (1.2 g, 1.9 mmol, 1eq) was dissolved in MeOH (90 mL), followed by addition of sodiummethoxide (0.21 g, 3.8 mmol, 2 eq). The mixture was stirred at r.t. for16 h, then concentrated under reduced pressure. The residual materialwas purified by flash column chromatography (eluent: MeOH/DCM=1/100) toafford 6-¹⁸O-2-N-butyryl-1,3,4-tri-O-benzyl-D-glucosamine (0.89 g,89.8%). This tribenzyl derivative (0.89 g, 1.7 mmol, 1 eq) was dissolvedin MeOH (25 mL), followed by addition of acetic acid (25 mL), and thenPd/C (10%, 0.8 g). The mixture was stirred at 30° C. under H₂ atmospherefor 48 h, then filtered. The filtration was concentrated under reducedpressure. Then DCM (25 mL) was added to the residual material and themixture was stirred for 10 min. The solid was collected by filtration,and dried, affording the title compound (0.36 g, 84.3%) with 97.5%abundance of ¹⁸O-isotope at 6-O-position: ¹H NMR (500 MHz, D₂O) δ 5.23(d, J=3.6 Hz, 0.65H), 4.74 (d, J=8.7 Hz, 0.4H), 3.98-3.85 (m, 2.57H),3.84-3.68 (m, 1.94H), 3.61-3.44 (m, 1.47H), 2.32 (t, J=7.2 Hz, 2H), 1.66(q, J=7.4 Hz, 2H), 0.95 (td, J=7.4, 3.9 Hz, 3H). ¹³C NMR (125 MHz, D₂O)δ 177.54, 94.99, 90.88, 75.93, 73.83, 71.55, 70.55, 70.16, 69.94, 60.75,60.59, 56.55, 53.99, 37.98, 37.57, 18.99, 12.65; m/z (ESI⁻): 250.2;(ESI⁻): 252.1.

Example 51. Preparation of2-N-4-O-dibutyryl-6-O-(2-hydroxybenzoyl)-D-glucosamine (Compound 91)

Butyric anhydride (0.742 g, 4.69 mmol, 1.5 eq) was added to a solutionof 1,3-di-O-benzyl-2-N-butyryl-6-O-(2-benzyloxybenzoyl)-D-glucosamine (2g, 3.13 mmol, 1 eq) and DMAP (0.038 g, 0.31 mmol, 0.1 eq) in pyridine(20 mL). The mixture was stirred at 35° C. for 2 h. Pyridine was removedunder reduced pressure. The residual material was purified by flashcolumn chromatography (eluent: MeOH/DCM=1/100˜1/100) to afford1,3-di-O-benzyl-2-N-4-O-dibutyryl-6-O-(2-benzyloxybenzoyl)-D-glucosamine(2 g, 90% yield) as a white solid. This solid (2. g, 2.82 mmol, 1 eq)was dissolved in MeOH (15 mL) and AcOH (15 mL), followed by addition ofPd/C (1 g, 10%, wet) under H₂. The mixture was stirred at 25° C. for 40h. The mixture was filtered and concentrated under reduced pressure. Theresidual material was purified by flash column chromatography (eluent:MeOH/DCM=1/100˜1/30) to afford the title compound (0.24 g, 20% yield) asa white solid. ¹H NMR (500 MHz, CD₃OD) δ 7.94 (d, J=7.5 Hz, 1H), 7.49(t, J=7.5 Hz, 1H), 6.93 (dd, J=18.0, 9.0 Hz, 2H), 5.59 (s, 0.007H), 5.49(s, 0.002H), 5.19 (d, J=2.0 Hz, 0.85H), 5.06 (t, J=9.5 Hz, 0.97H), 4.77(d, J=7.0 Hz, 0.17H), 4.57 (d, J=14.5 Hz, 0.32H), 4.49 (d, J=11.5 Hz,0.83H), 4.39 (dd, J=12.0, 4.5 Hz, 0.96H), 4.31 (d, J=9.5 Hz, 0.82H),4.04 (dd, J=10.5, 2.5 Hz, 0.83H), 3.94 (t, J=10.0 Hz, 0.81H), 3.85 (d,J=7.5 Hz, 0.14H), 3.80-3.71 (m, 0.26H), 2.45-2.32 (m, 2H), 2.25 (t,J=7.5 Hz, 2H), 1.78-1.54 (m, 4H), 0.96 (q, J=13.5, 6.5 Hz, 6H). ¹³C NMR(125 MHz, CD₃OD) δ 175.69, 175.23, 173.14, 169.52, 161.31, 135.60,129.97, 119.00, 116.98, 112.14, 95.74, 91.28, 72.05, 71.68, 71.30,68.99, 67.22, 63.33, 63.15, 57.54, 54.42, 37.94, 37.52, 35.57, 18.98,17.96, 12.63. m/z (ES⁺) 340.0, m/z (ES⁻) 338.0.

Example 52. Preparation of2-N-butyryl-6-O-(2-N-D-glucosaminocarbonyl)-D-glucosamine (Compound 92)

TBSCl (18.7 g, 124 mmol, 2 eq) was added to a solution of1,3-di-O-benzyl-2-N-butyryl-D-glucosamine (20 g, 62 mmol, 1 eq) and DMAP(0.75 g, 6.2 mmol, 0.1 eq) in pyridine (200 mL). The mixture was stirredat r.t. under N₂ atmosphere for 3 h, and pyridine was removed underreduced pressure. The residual material was dissolved with EtOH (40 mL)and added to H₂O (400 mL). The white suspension was filtered, and thefilter cake washed with water, then dried at 50° C. under vacuum to give1,3-di-O-benzyl-2-N-butyryl-6-O-trimethylsilyl-D-glucosamine (25 g,74%). The product was dissolved (25 g, 46 mmol, 1 eq) in DMF (300 mL),followed by addition of benzyl bromide (9.6 g, 56.1 mmol, 1.2 eq). Tothe mixture was added NaH (2.8 g, 69.2 mmol, 2.7 eq) in batches whilekeeping the temperature below 0° C. The mixture was warmed to r.t. andstirred at r.t. for 4 h. The mixture was poured into H₂O (2000 mL). Themixture was stirred at r.t. for 1 h. The solid was collected byfiltration, washed with H₂O (100 mL) and PE (100 mL) subsequently, anddried, giving1,3,4-tri-O-benzyl-2-N-butyryl-6-O-trimethylsilyl-D-glucosamine (27 g,92.6%). The obtained compound (27 g, 42.6 mmol, 1 eq) was dissolved inDCM (15 mL), treated with 4 M HCl in Dioxane (27 mL). The mixture wasstirred at r.t. for 2 h, and concentrated under reduced pressure. Theresidual material was purified by flash column chromatography (eluent:MeOH/DCM=1/200˜1/40) to afford1,3,4-tri-O-benzyl-2-N-butyryl-D-glucosamine (16 g, 72.3%). The compoundthus obtained (5.2 g, 10 mmol, 1 eq) and 4-nitrophenyl carbonochloridate(2.4 g, 12 mmol, 1.2 eq) were dissolved in DCM (100 mL), followed byaddition of triethylamine (1.5 g, 15 mmol, 1.5 eq). The mixture wasstirred at r.t. for 16 h, and solvent was removed under reducedpressure. The residual material was purified by flash columnchromatography (eluent: MeOH/DCM=1/200) to afford1,3,4-tri-O-benzyl-2-N-butyryl-6-O-(4-nitrobenzyloxycarbonyl)-D-glucosamine(4.3 g, 62.8%). This product (1.05 g, 1.5 mmol, 1 eq) and D-glucosaminehydrochloride (0.32 g, 1.5 mmol, 1 eq) were dissolved in DMF (50 mL),followed by addition of triethylamine (0.24 g, 2.4 mmol, 1.5 eq). Themixture was stirred at r.t. for 16 h, and solvent was removed underreduced pressure. The residual material was purified by flash columnchromatography (eluent: MeOH/DCM=1/200) to give1,3,4-tri-O-benzyl-2-N-butyryl-6-O-(2-N-D-glucosaminocarbonyl)-D-glucosamine(1.1 g, 98.9%). The latter compound (1.1 g, 1.5 mmol, 1 eq) wasdissolved in MeOH (35 mL), followed by addition of Pd/C (10%, 0.8 g) andacetic acid (35 mL). The mixture was stirred at 30° C. under H₂atmosphere for 16 h. The mixture was filtered. The filtration wasconcentrated under reduced pressure. The mixture was filtered. Thefiltration was concentrated under reduced pressure. Then DCM (15 mL) wasadded to residual material and stirred for 10 min, the solid wasfiltered, and dried to afford compound 92 (0.46 g, 66.6%). ¹H NMR (500MHz, D₂O) δ 5.20 (d, J=3.5 Hz, 0.64H), 5.16 (d, J=3.5 Hz, 0.81H),4.40-4.21 (m, 1.5H), 4.00 (dd, J=9.6, 2.8 Hz, 0.7H), 3.93-3.78 (m,2.37H), 3.78-3.64 (m, 2.66H), 3.64-3.57 (m, 0.77H), 3.55-3.39 (m,2.62H), 3.33 (d, J=14.1 Hz, 0.19H), 2.25 (t, J=7.2 Hz, 2H), 1.59 (q,J=7.4 Hz, 2H), 0.88 (td, J=7.4, 4.0 Hz, 3H). ¹³C NMR (126 MHz, D₂O) δ177.81, 177.57, 158.34, 158.08, 95.10, 91.23, 90.97, 81.77, 75.94,73.95, 73.75, 73.60, 71.56, 71.08, 70.44, 70.08, 70.01, 69.85, 69.68,69.63, 63.88, 60.77, 60.63, 58.42, 56.48, 55.64, 53.92, 37.99, 37.58,19.00, 12.66; m/z (ESI⁻): 453; (ESI⁺): 455.1.

Example 53. Preparation of1,3,4-tri-O-acetyl-2-N-butyryl-6-O-(2-acetyloxybenzoyl)-D-glucosamine(Compound 93)

Acetic anhydride (2.22 g, 2.2 mmol, 4 eq) was added to a solution of2-N-butyryl-6-O-(2-hydroxybenzoyl)-D-glucosamine (2 g, 5.4 mmol, 1 eq)and DMAP (0.032 g, 0.27 mmol, 0.05 eq) in pyridine (50 mL). The mixturewas stirred at 35° C. for 2 h. Pyridine was removed under reducedpressure. The residue was purified by flash column chromatography(eluent: MeOH/DCM=1/100˜1/70) to afford the title compound (0.9 g, 31%yield) as a white solid. ¹H NMR (500 MHz, CD₃OD) δ 8.02 (d, J=7.5 Hz,1H), 7.64 (t, J=7.5 Hz, 1H), 7.39 (t, J=7.5 Hz, 1H), 7.16 (d, J=8.0 Hz,1H), 6.14 (s, 1H), 5.34 (t, J=10.0 Hz, 1H), 5.15 (t, J=9.5 Hz, 1H),4.51-4.39 (m, 2H), 4.36 (d, J=12.5 Hz, 1H), 4.24 (d, J=9.0 Hz, 1H), 2.37(s, 3H), 2.19 (s, 3H), 2.15 (t, J=7.0 Hz, 2H), 2.02 (s, 3H), 1.98 (s,3H), 1.79-1.42 (m, J=14.0, 6.9 Hz, 2H), 0.89 (t, J=7.0 Hz, 3H). ¹³C NMR(125 MHz, CD₃OD) δ 175.18, 170.52, 169.92, 169.81, 169.37, 164.16,150.62, 133.96, 131.37, 125.83, 123.60, 122.90, 90.06, 70.35, 69.70,68.59, 62.32, 50.40, 37.11, 19.64, 19.35, 19.25, 19.19, 18.89, 12.45.m/z (ESI⁺) 537.9.

Example 54. Preparation of2-N-butyryl-6-O-((3-carboxy-1-propyl)aminocarbonyl)-D-glucosamine(Compound 94)

1,3,4-Tri-O-benzyl-2-N-butyryl-6-O-(4-nitrobenzoyl)-D-glucosamine (1.4g, 2 mmol, 1 eq) and 4-aminobutanoic acid (0.2 g, 2 mmol, 1 eq) weredissolved in DMF (200 mL), followed by addition of triethylamine (0.3 g,3 mmol, 1.5 eq). The mixture was stirred at r.t. for 16 h, and DMF wasremoved under reduced pressure. The residual material was purified byflash column chromatography (eluent: MeOH/DCM=1/50) to afford1,3,4-tri-O-benzyl-2-N-butyryl-6-O-((3-carboxy-1-propyl)aminocarbonyl)-D-glucosamine(1.05 g, 81.0%). The obtained compound (1.05 g, 1.65 mmol, 1 eq) wasdissolved in MeOH (10 mL), followed by addition of Pd/C (10%, 0.8 g) andacetic acid (10 mL). The mixture was stirred at 30° C. under H₂atmosphere for 16 h. The mixture was filtered. The filtration wasconcentrated under reduced pressure. The residual material was dissolvedwith water and dried at −40° C. under vacuum to give the title compound(510 mg, 81.7%); ¹H NMR (500 MHz, D₂O) δ 8.09 (d, J=10.1 Hz, 0.03H),8.01 (d, J=8.9 Hz, 0.26H), 5.14 (d, J=3.5 Hz, 0.59H), 4.68 (d, J=8.5 Hz,0.43H), 4.44-4.09 (m, 1.87H), 4.05-3.78 (m, 1.43H), 3.77-3.60 (m,1.35H), 3.60-3.37 (m, 1.40H), 3.14 (t, J=6.7 Hz, 2H), 2.38 (t, J=7.3 Hz,2H), 2.23 (q, J=7.1 Hz, 2H), 1.76 (p, J=6.8 Hz, 2H), 1.58 (h, J=7.5 Hz,2H), 0.87 (t, J=7.3 Hz, 3H). ¹³C NMR (125 MHz, D₂O) δ 178.22, 177.77,177.52, 158.29, 158.24, 95.07, 90.93, 73.76, 73.60, 70.43, 70.14, 70.04,69.78, 69.66, 63.52, 56.47, 53.90, 52.19, 39.67, 37.97, 37.56, 31.00,30.96, 24.33, 18.98, 12.63; m/z (ESI⁻): 376.9.

Example 55. General Method for Pharmacokinetic Study of Compounds of theInvention

A test compound is dissolved in water at a concentration determined bythe desired dose and dosing volume for the specific animal to which thecompound is to be administered. A calculated volume of dosing solutionis administered to the animal (PO, SQ, IP, or IV). A blood sample iscollected following administration of the test compound at specific timepoints (such as 0 minutes (min), 5 min, 10 min, 15 min, 30 min, 1 hour(h), 1.5 h, 2 h, 3 h, 4, 6 h, etc.). The blood sample is converted to aplasma sample using standard techniques. The plasma samples are analyzedto determine the concentration of the test compound and, in some cases,GlcNBu.

Example 56. Pharmacokinetic Studies for Compounds in Sprague-Dawley (SD)Rats

According to the above general procedure, SD rats were grouped randomlyinto groups of six (n=6). The test compound, GlcNBu or a compoundprovided herein, was administered to the animals by oral gavage at adose of 0.93 mmol/kg. For illustration purposes, GlcNBu was given at anoral dose of 232 mg/kg (0.93 mmol/kg), and compound 16 was administeredat an equal molar dose (0.93 mmol/kg, i.e., 362 mg/kg). At pre-set timepoints, blood was taken through orbital venous plexus extraction, andthe samples were analyzed using LC/MS-MS to determine the GlcNBuconcentration in the plasma.

The results of an exemplary pharmacokinetic study are presented in FIGS.1 and 2. The plasma GlcNBu concentration-time curves following an oraladministration of GlcNBu and compound 16 are shown in FIG. 1. In thefigure, Curves labeled with -●- and -▴- represent plasma GlcNBuconcentration following oral administration of GlcNBu (232 mg/kg, or0.93 mmol/kg) and compound 16 (232 mg/kg, or 0.93 mmol/kg),respectively. The results indicate that at the mole-equivalent oraldose, compound 16 improved plasma drug exposure significantly, withabout 10-fold increase of Cmax for the plasma GlcNBu concentration. FIG.2A and FIG. 2B show examples of other compounds of the invention,presented in plasma GlcNBu concentration versus time curves; a summaryof pharmacokinetic parameters for these compounds is given in Table 4and Table 5.

TABLE 4 PK parameters for GlcNBu after administration of the indicatedcompound. Compound Parameter Unit 5 6 12 14 18 GlcNBu AUC(0-t) ug/L*h10850.9 11179.2 12412 10799 9895 7938 AUC(0-∞) ug/L*h 10963.3 22557.616842 11704 10348 7992 t_(1/2) h 0.7 5.8 2.677 1.603 1.18 0.741 Tmax h1.5 1.5 2 1 1.25 1 Vz/F L/kg 20.9 83.2 51.15 44.08 3.47 31.184 CLz/FL/h/kg 20.4 9.9 13.24 19.05 1.96 29.157 Cmax ug/L 4496 2685 3483 43453570 3303

TABLE 5 PK parameters for GlcNBu after administration of the indicatedcompound¹. Parameter (unit) Com- AUC_(0-t) AUC_(0-∞) pound (μg/ (μg/t_(1/2z) T_(max) Vz/F CLz/F C_(max) # L*h) L*h) (h) (h) (L/kg) (L/h/kg)(μg/L) 27 8597 8918 2 1 77 33 4890 30 512 810 2 2 86 25 276 41 1930319890 1 0 23 11 17017 56 2190 2520 2 2 18 8 588 73 8740 9346 2 2 64 254300 74 662 889 1 0 28 22 426 75 (—) (—) (—) (—) (—) (—) (—) 76 (—) (—)(—) (—) (—) (—) (—) 77 874 1903 4 2 68 11 345 78 4582 5038 2 0 9 4 496079 (—) (—) (—) (—) (—) (—) (—) 80 19988 19990 0 1 1 1 18770 82 5932 59701 2 3 3 2287 83 3037 3638 2 3 183 60 657 84 6532 9919 4 1 10 2 1723 853156 3189 1 1 7 6 1180 86 1609 1941 1 2 187 113 678 87 7062 7157 1 0 4 33797 88 17129 17767 1 1 2 1 8967 89 1757 1942 1 2 10 10 1110 91 43555048 2 1 13 4 1700 92 1165 1166 1 1 11 25 901 93 1060 1080 1 0 27 20 90694 (—) (—) (—) (—) (—) (—) (—) ¹(—): not detected

Example 57. Evaluation of a novel compound in monosodiumiodoacetate-induced osteoarthritis (MIA) model in rat knee

Osteoarthritis was induced by intra-articular (i.a.) injection of MIAsolution in the rat knee joint as follows: Briefly, rats wereanesthetized with isoflurane and given a single i.a. administration of 2mg of MIA dissolved in saline through the intrapatellar ligament of theright knee. MIA was administered in a volume of 50 μL. Basal readingswere established using a group of control rats injected with 10% ethanolin water. Rats were randomized by initial body weight to groups of 6 or7. After MIA injection, the MIA groups began treatment with eithervehicle, or a test compound at a preset dose regime for a period of 28days. Clinical observations were recorded, including body weight, jointswelling, and weight bearing, on pre-induction day (day 0), day 3, 5, 7,14, 21 and/or 28. At the end of the study, the animals were euthanizedby CO₂ and sacrificed. Joint samples including the tibia and femur weresectioned in the coronal plane and stained using both H&E andSafranin-O. Knee joints were examined and scored for cartilagedegeneration, the presence of osteophytes, the amount and extent ofcalcified cartilage and subchondral bone damage, and the amount ofsynovial membrane inflammation using the Osteoarthritis Research SocietyInternational (OARSI) scoring system put forth in 2010 (Kraus, V. B. etal., Osteoarthritis Cartilage, 2010, Suppl 3:S35-52).

Example 58. Study of Compound 16 in MIA Model

Studies of compound 16 in the MIA model were conducted as describedabove. The MIA animals were randomized into four groups (n=6), andtreated with vehicle (Group 1 (G1), or compound 16 at 234 mg/kg (Group 2(G2)) or 468 mg/kg (Group 3 (G3)). The weight bearing results are givenin Table 6 below. On day 5, all the compound-treated groups showedsignificant increases in weight bearing on the back-right leg. The trendfor increasing weight bearing was clear throughout the treatment periodafter day 5 for both treated groups, with significant increases at thehigh dose (G3) on day 14. Total histological scores from the vehiclegroup and the treated groups are shown in FIGS. 4A-4H.

TABLE 6 Weight bearing results for rats in MIA model treated withcompound 16. Pre-Injection Day Day Day Day Day Day Animal (Day 0) 3 5 714 21 28 Group % % % % % % % 1 Mean 50.49 34.79 27.81 34.04 36.38 40.6443.01 SD 1.43 5.35 5.62 5.89 4.54 3.31 2.98 2 Mean 50.49 32.07 35.76**37.72 40.86 44.12 45.90 SD 1.01 4.46 3.00 1.94 3.18 2.47 1.05 3 Mean50.25 34.56 37.40** 39.23 41.68* 44.25 44.98 SD 1.40 3.89 3.12 3.07 1.922.40 1.52 *Vs Group 1, P < 0.05; **Vs Group 1, P < 0.01

The results indicate that osteophytes in the high dose group weresignificantly decreased compared with the vehicle group. The high dosetreated group showed a clear trend of lowering all other mean values foreach histological parameter evaluated in the study, including the Natureof Predominant Tissue, Surface Regularity, Structural Integrity,Chondrocyte Clustering, Degenerative Changes in Cartilage, InflammatoryResponse in Subchondral Bone Region, and Neo-Vascularization. The lowermorphological and numerical changes of chondrocytes and closer to normalnature of the tissue indicated that compound 16 slowed the articularcartilage degeneration in this MIA-induced OA rat model.

Example 59. Study of Compound 16 in Medial Meniscus Transection (MMT)Model in Rats

In the rat MMT model, the unilateral knee (right knee) was cleaned andprepped for surgery. An incision was made over the medial aspect of thefemoro-tibial joint. The medial collateral ligament was exposed viablunt dissection and transected to reflect the meniscus toward thefemur. A full thickness cut was made through the meniscus at itsnarrowest point. The joint space was returned to normal, and the skinwas closed and the animal allowed to recover. For the present study, atsecond day post MMT induction animals, G1 and G2 animals were treatmentwith vehicle and test compound 16 respectively. Animals were dosed 4times every day, and were dosed by gavage for 4 weeks.

After MMT, weight bearing of the right paw was decreased sharply in bothgroups (see Table 7; FIG. 5) until Day 3. The rebounds of the weightbearing on the right paw after Day 3 were larger in G2 than in G1,moreover, it was significantly increased in G2 as compared with G1 onDay 3 and Days 14-28.

TABLE 7 Weight bearing results for rats in MMT model treated withcompound 16. Pre- Weight bearing injection Day 3 Day 5 Day 7 Day 14 Day21 Day 28 Group (right paw, %) % % % % % % % G1 Mean 50.21 33.88 38.0638.89 39.85 40.30 40.83 SD 0.71 2.17 2.84 1.26 1.68 1.03 1.66 G2 Mean49.55 36.68* 39.76 40.68 42.71* 43.73** 44.06** SD 0.98 2.06 2.01 3.162.20 1.01 1.09 *VsG1, P < 0.05; **VsG1, P < 0.01

Data (see Table 8; FIGS. 6A-6I) from histology parameters showed thatthe G2 had values in all parameters lower than that of the G1.Specifically, degeneration changes of chondrocyte clustering of the G2(Compound 16) was significantly lower as compared with the G1.

TABLE 8 Histopathology evaluation results. G1 G2 Histopathologicalparameter Mean SD Mean SD Nature of predominant tissue (0-4) 1.67 0.521.00 0.63 Surface regularity (0-4) 2.00 0.89 1.67 0.52 Structuralintegrity (0-4) 1.67 0.52 1.17 0.41 Chondrocyte clustering (0-4) 1.830.41 1.17* 0.41 Degenerative changes in cartilage (0-4) 1.33 0.52 1.170.75 Inflammatory response in subchondral 0.17 0.41 0.00 0.00 boneregion (0-4) Neo-vascularization (0-4) 0.17 0.41 0.00 0.00 Osteophytes(0-4) 1.33 1.03 1.17 0.75 Total scoring 10.17 2.93 7.33 1.63 * Vs G1, P< 0.05

Current experiments demonstrated that the G2 (Compound 16) hadsignificantly more weight bearing on the injured leg starting on Day 3and Day 14 through Day 28, and significantly less cartilage clusteringdegeneration. The above observations demonstrate the efficacy andsupport the use of the test compound q.i.d. to treat an MMT-inducedmodel of osteoarthritis.

From a certain perspective, embodiments of the present invention can besummarized as follows, structured in numbered clauses:

CLAUSE 1. A compound of Formula (A), or a pharmaceutically acceptablesalt or ester thereof:

where:

X is O, N, or S;

R is a substituted or unsubstituted C₂ to C₁₈ substituent selected fromlinear or branched alkyl, alkenyl, alkynyl, aryl, heteroaryl, arylalkyl,alkylaryl, cycloalkyl, and alkyl comprising a cyclic or a heterocyclicmoiety, or

R is a substituted or unsubstituted C₂ to C₁₂ substituent selected fromlinear or branched alkyl, alkenyl, alkynyl, aryl, heteroaryl, arylalkyl,alkylaryl, cycloalkyl, and alkyl comprising a cyclic or a heterocyclicmoiety;

R² is hydrogen, acyl, or alkyl; and

R¹, R³, R⁴, and R⁵ are independently hydrogen, substituted orunsubstituted alkyl, aryl, arylalkyl, alkylaryl, cyclic or heterocyclicmoiety, or acyl group derived from a carboxylic acid, an amino acid, ora peptide, optionally with a protecting group, a phosphonyl group, or asulfonyl group, provided that R¹, R³, R⁴, and R⁵ are not all hydrogen atthe same time, or

one or more of R¹, R³, R⁴, and R⁵ are independently selected fromalkoxycarbonyl, aryloxycarbonyl, and arylalkoxycarbonyl, or

R³ and R⁴, taken together with the atoms to which they are attached,form a substituted or unsubstituted heterocyclic ring, or

R⁴ and R⁵, together with the atoms to which they are attached, form asubstituted or unsubstituted heterocyclic ring; and

n is an integer from 1 to 6.

CLAUSE 2. The compound of clause 1, wherein one or more of R¹, R³, R⁴,and R⁵ is independently in the form of Q¹C(═O)—, where Q¹ is selectedfrom unsubstituted or substituted alkyl, alkenyl, alkynyl, aryl,heteroaryl, carbocyclic, heterocyclic group with or without asubstituent group, alkoxy, aryloxy, arylalkyloxy, and alkylaryloxy; andan amino or hydroxyl group in Q¹, if present, is optionally substituted.

CLAUSE 3. The compound of clause 1 or 2, wherein the compound is acompound of Formula (I), or a pharmaceutically acceptable salt or esterthereof:

where R, R¹ through R⁵, and n are defined as in clause 1.

CLAUSE 4. The compound of clause 1 or 2, wherein the compound is acompound of Formula (II), or a pharmaceutically acceptable salt or esterthereof:

where R¹ through R⁵, and n are defined as in clause 1.

CLAUSE 5. The compound of clause 1 or 2, wherein the compound is acompound of Formula (III), or a pharmaceutically acceptable salt orester thereof:

where R¹, R³ through R⁵, and n are defined as in clause 1.

CLAUSE 6. The compound of clause 1 or 2, wherein the compound is acompound of Formula (IV), or a pharmaceutically acceptable salt or esterthereof:

where:

R¹, R³, R⁴, and R⁵ are independently hydrogen, substituted orunsubstituted alkyl, aryl, arylalkyl, alkylaryl, cyclic or heterocyclicmoiety, or acyl group derived from a carboxylic acid, an amino acid, ora peptide, optionally with a protecting group, a phosphonyl group, or asulfonyl group, provided that R¹, R³, R⁴, and R⁵ are not all hydrogen atthe same time, or

one or more of R¹, R³, R⁴, and R⁵ are independently selected fromalkoxycarbonyl, aryloxycarbonyl, and arylalkoxycarbonyl, or

R³ and R⁴, taken together with the atoms to which they are attached,form a substituted or unsubstituted heterocyclic ring, or

R⁴ and R⁵, together with the atoms to which they are attached, form asubstituted or unsubstituted heterocyclic ring.

CLAUSE 7. The compound of clause 6, wherein R³, R⁴, and R⁵ areindependently H, C₁-C₁₂ alkyl, acyl, or an amino acid, provided that R¹,R³, R⁴, and R⁵ are not all H at the same time.

CLAUSE 8. The compound of clause 6, wherein R¹ is H, and R³, R⁴, and R⁵are independently H, C₁-C₆ alkyl, acyl, or a natural amino acid residue,provided that R³, R⁴, and R⁵ are not all H at the same time.

CLAUSE 9. The compound of clause 6, wherein R¹ and R³ are H, and R⁴ andR⁵ are independently selected from H, C₁-C₆ acyl, or an unsubstituted orsubstituted natural amino acyl group.

CLAUSE 10. The compound of any one of clauses 1 to 9, wherein thecompound is an alpha-anomer, a beta-anomer, or a mixture of alpha- andbeta-anomers.

CLAUSE 11. The compound of any one of clauses 1 to 10, wherein thecompound is not a derivative of N-acetyl glucosamine.

CLAUSE 12. The compound of any one of clauses 1 to 11, which is acompound set forth in any one of Tables 1, 2, and 3, or is any one ofcompound Nos. 1-172; or a pharmaceutically acceptable salt or esterthereof.

CLAUSE 13. The compound of any one of clauses 1 to 12, wherein one ormore of the C, H, O, and/or N atoms in the compound is isotope-enriched.

CLAUSE 14. The compound of clause 13, wherein the C atoms in thecompound are independently ¹²C, ¹³C, or ¹⁴C.

CLAUSE 15. The compound of clause 13 or 14, wherein the H atoms areindependently ¹H, D (²H), or T (³H).

CLAUSE 16. The compound of any one of clauses 13 to 15, wherein theO-atoms are independently ¹⁶O, ¹⁷O, or ¹⁸O.

CLAUSE 17. The compound of any one of clauses 13 to 16, wherein the Natoms are independently ¹N or ¹N.

CLAUSE 18. A pharmaceutical composition comprising the compound of anyone of clauses 1 to 17 and a pharmaceutically acceptable carrier.

CLAUSE 19. The pharmaceutical composition of clause 18, wherein thecomposition is suitable for oral administration or for topicaladministration.

CLAUSE 20. The pharmaceutical composition of clause 18 or 19, whereinthe composition is in the form of a hard shell gelatin capsule, a softshell gelatin capsule, a cachet, a pill, a tablet, a lozenge, a powder,a granule, a pellet, a pastille, or a dragee.

CLAUSE 21. The pharmaceutical composition of clause 18 or 19, whereinthe composition is in the form of a solution, an aqueous liquidsuspension, a non-aqueous liquid suspension, an oil-in-water liquidemulsion, a water-in-oil liquid emulsion, an elixir, a syrup, anointment, or a medical patch.

CLAUSE 22. The pharmaceutical composition of any one of clauses 18 to21, wherein the composition is enteric coated.

CLAUSE 23. The pharmaceutical composition of any one of clauses 18 to22, wherein the composition is formulated for controlled release.

CLAUSE 24. A method for the prevention or treatment of a bone or jointdisorder comprising administering an effective amount of the compound ofany one of clauses 1 to 17 or the pharmaceutical composition of any oneof clauses 18 to 23 to a subject in need thereof, such that the bone orjoint disorder is prevented or treated in the subject.

CLAUSE 25. The method of clause 24, wherein the bone or joint disorderis osteoporosis.

CLAUSE 26. The method of clause 24, wherein the bone or joint disorderis osteopenia.

CLAUSE 27. The method of clause 24, wherein the bone or joint disorderis arthritis.

CLAUSE 28. The method of clause 27, wherein the arthritis isosteoarthritis, inflammatory arthritis, traumatic arthritis,degenerative arthritis or dysplastic arthritis.

CLAUSE 29. The method of clause 28, wherein the inflammatory arthritisis rheumatoid arthritis or psoriatic arthritis.

CLAUSE 30. The method of any one of clauses 24 to 29, wherein thesubject is a mammal, e.g., a human.

CLAUSE 31. A method for increasing the therapeutic effectiveness ofGlcNBu in a subject in need thereof, comprising administering aneffective amount of the compound of any one of clauses 1 to 17 or thepharmaceutical composition of any one of clauses 18 to 23 to thesubject, such that the therapeutic effectiveness of GlcNBu is increasedas compared to administration of GlcNBu.

CLAUSE 32. The method of clause 31, wherein said increasing thetherapeutic effectiveness of GlcNBu comprises one or more of thefollowing: increasing bioavailability of GlcNBu; increasing AUC ofGlcNBu in blood or plasma; increasing C_(max) of GlcNBu; increasingT_(max) of GlcNBu; increasing t of GlcNBu; improving therapeuticbio-distribution of GlcNBu; increasing therapeutic level of GlcNBu in aselected tissue; increasing bioabsorption of GlcNBu; reducing metabolismof GlcNBu; and reducing side effects of GlcNBu.

CLAUSE 33. The method of clause 31 or 32, wherein the subject suffersfrom a bone or joint disorder.

CLAUSE 34. The method of clause 33, wherein the bone or joint disorderis osteoporosis, osteopenia or arthritis.

CLAUSE 35. The method of any one of clauses 31 to 34, wherein thesubject is a mammal, e.g., a human.

CLAUSE 36. A kit comprising the compound of any one of clauses 1 to 17or the pharmaceutical composition of any one of clauses 18 to 23 andinstructions for use thereof.

CLAUSE 37. A method for treating osteoporosis in a subject, comprisingadministering an effective amount of the compound of any one of clauses1 to 17 or the pharmaceutical composition of any one of clauses 18 to 23to the subject, such that osteoporosis is treated in the subject.

CLAUSE 38. The method of clause 37, wherein compound No. 16 isadministered to the subject.

CLAUSE 39. A method for treating osteoarthritis in a subject, comprisingadministering an effective amount of the compound of any one of clauses1 to 17 or the pharmaceutical composition of any one of clauses 18 to 23to the subject, such that osteoporosis is treated in the subject.

CLAUSE 40. The method of clause 39, wherein compound No. 16 isadministered to the subject.

CLAUSE 41. A method for treating a bone or joint disorder comprisingadministering an effective amount of the compound of any one of claims 1to 10 or the pharmaceutical composition of any one of claims 11 to 15 toa subject in need thereof in combination with one or more secondtherapeutic agent, such that the bone or joint disorder is prevented ortreated in the subject.

CLAUSE 42. The method of clause 41, wherein the one or more secondtherapeutic agent is a bisphosphonate, denosumab, calcitonic, aselective estrogen receptor modulators (SERM) such as raloxifene,teriparatide, duloxetine, and/or a nonsteroidal anti-inflammatory drugs(NSAIDs).

Although this invention is described in detail with reference toembodiments thereof, these embodiments are offered to illustrate but notto limit the invention. It is possible to make other embodiments thatemploy the principles of the invention and that fall within its spiritand scope as defined by the claims appended hereto.

The contents of all documents and references cited herein are herebyincorporated by reference in their entirety.

What is claimed is:
 1. A compound of Formula (II), or a pharmaceutically acceptable salt or ester thereof:

where: R¹ is hydrogen, substituted alkyl, or acyl group derived from a carboxylic acid, an amino acid, or a peptide, optionally with a protecting group, a phosphonyl group, or a sulfonyl group; R² is hydrogen, acyl, or alkyl; R³, R⁴, and R⁵ are independently hydrogen, substituted or unsubstituted alkyl, aryl, arylalkyl, alkylaryl, cyclic or heterocyclic moiety, or acyl group derived from a carboxylic acid, an amino acid, or a peptide, optionally with a protecting group, a phosphonyl group, or a sulfonyl group, provided that R³, R⁴, and R⁵ are not all acyl group at the same time; and n is an integer from 1 to 6; provided that R¹, R³, R⁴, and R⁵ are not all hydrogen at the same time; or one or more of R¹, R³, R⁴, and R⁵ are independently selected from alkoxycarbonyl, aryloxycarbonyl, and arylalkoxycarbonyl; or R³ and R⁴, taken together with the atoms to which they are attached, form a substituted or unsubstituted heterocyclic ring; or R⁴ and R⁵, together with the atoms to which they are attached, form a substituted or unsubstituted heterocyclic ring.
 2. The compound of claim 1, wherein the compound is a compound of Formula (III), or a pharmaceutically acceptable salt or ester thereof:

where R¹, R³ through R⁵, and n are defined as in claim
 1. 3. The compound of claim 1, wherein the compound is a compound of Formula (IV), or a pharmaceutically acceptable salt or ester thereof:

where: R¹, R³, R⁴, and R⁵ are defined as in claim
 1. 4. The compound of claim 1, wherein the compound is an alpha-anomer, a beta-anomer, or a mixture of alpha- and beta-anomers.
 5. A compound which is

or a pharmaceutically acceptable salt or ester thereof.
 6. The compound of claim 1, wherein the C, H, O, and/or N atoms in the compound are each independently selected from atoms of natural abundance and isotope-enriched atoms.
 7. The compound of claim 6, wherein the C atoms in the compound are independently selected from ¹²C, ¹³C, and ¹⁴C; the H atoms in the compound are independently selected from ¹H, ²H, and ³H; the O-atoms in the compound are independently selected from ¹⁶O, ¹⁷O, and ¹⁸O; and the N atoms in the compound are independently selected from ¹⁴N and ¹⁵N.
 8. A pharmaceutical composition comprising the compound of any claim 1 and a pharmaceutically acceptable carrier.
 9. The pharmaceutical composition of claim 8, wherein the composition is suitable for oral or topical administration.
 10. The pharmaceutical composition of claim 8, wherein the composition is in the form of a hard shell gelatin capsule, a soft shell gelatin capsule, a cachet, a pill, a tablet, a lozenge, a powder, a granule, a pellet, a pastille, or a dragee.
 11. The pharmaceutical composition of claim 8, wherein the composition is in the form of a solution, an aqueous liquid suspension, a non-aqueous liquid suspension, an oil-in-water liquid emulsion, a water-in-oil liquid emulsion, an elixir, a syrup, an ointment, or a medical patch.
 12. The pharmaceutical composition of claim 8, wherein the composition is enteric coated or formulated for controlled release.
 13. A method for the prevention or treatment of a bone or joint disorder comprising administering an effective amount of the compound of claim 1 to a subject in need thereof, such that the bone or joint disorder is prevented or treated in the subject.
 14. The method of claim 13, wherein the bone or joint disorder is osteoporosis, osteopenia, and/or arthritis.
 15. The method of claim 14, wherein the arthritis is osteoarthritis, inflammatory arthritis, traumatic arthritis, degenerative arthritis, dysplastic arthritis, rheumatoid arthritis or psoriatic arthritis.
 16. (canceled)
 17. The method of claim 13, wherein the subject is a mammal, optionally a human.
 18. A kit comprising the compound of claim 1 and instructions for use thereof.
 19. A method for the prevention or treatment of a bone or joint disorder comprising administering an effective amount of a compound to a subject in need thereof, such that the bone or joint disorder is prevented or treated in the subject, wherein the compound is selected from:

or a pharmaceutically acceptable salt or ester thereof.
 20. The method of claim 19, wherein the bone or joint disorder is osteoporosis, osteopenia, and/or arthritis.
 21. The method of claim 20, wherein the arthritis is osteoarthritis, inflammatory arthritis, traumatic arthritis, degenerative arthritis, dysplastic arthritis, rheumatoid arthritis or psoriatic arthritis.
 22. (canceled)
 23. (canceled) 